Date arithmetic under lib, audited file by file

Change: every-term-on-the-engine-calendar, task 1.1. Row Q8.23 of the competitor gap register, "is the calendar the deadline engine reads the same calendar the organisation administers".

This file is the deliverable the proposal asked for: not a count, but a verdict per file. The structural test tests/Unit/Architecture/EveryTermOnTheCalendarTest.php reads the verdict column of the table below, so a row here is a fact the build keeps true rather than a note somebody wrote once.

How the set was built

Patterns, over lib/**/*.php, file names only:

grep -rlE "modify\('[+-]|new DateInterval|->add\(|->sub\(|strtotime\('[+-]" lib/ --include=*.php

Read at 16f00124a (development, 2026-09-14). The same five patterns return the same 37 files at 9c478d810, the commit the proposal counted at, so the set has not drifted since the row was rated.

Two of the patterns, ->add( and ->sub(, are not anchored to a date type. They match IJobList::add() as readily as DateTimeImmutable::add(), which is why two of the 37 rows below have the verdict neither with the reason "not date arithmetic". The count is an upper bound on the problem, never the problem itself.

The verdicts

• statutory: a period the law names, ending on a date somebody can be held to. The beslistermijn, the bezwaartermijn, the ingebrekestelling grace, the hersteltermijn, the dwangsom window, the Woo decision term. Algemene termijnenwet art. 1 moves such a date off a Saturday, a Sunday or a recognised holiday, so it has to reach the working calendar.
• business: a date the organisation is judged on but the law does not name. It reads better on a working day and nobody is in breach when it does not.
• neither: a report window, a throughput bucket, a retention period in years, demo seed data, an intraday service norm, or a pattern false positive. A weekend cannot change the answer, so the calendar is not on its path.

Counts

	at 9c478d810 (proposal)	at 16f00124a (this change, before)	after this change (task 3.1)
files matching the patterns	37	37	38 (39 since case-recycle-window)
of those, reaching a working calendar	5	5	19
of those, verdict statutory	not measured	16	16
statutory files reaching a calendar	not measured	3	15
statutory files allowlisted with a named owner	not measured	n/a	1

case-recycle-window added a thirty-ninth, lib/Service/Recycle/RetentionClocks.php: it counts a lawful-purpose retention in months, which is the AVG side of the same question ArchivalNominationDeriver answers for the Archiefwet, and it carries the same verdict.

lifecycle-acts-on-the-case added a fortieth, lib/Service/Lifecycle/SilenceCloseService.php. It counts the administered period of silence a case type declares (REQ-LIFE-04) and the date the applicant is told the case will close on. It is deliberately NOT statutory: nothing in the Awb counts sixty days of nobody answering, the period is a gemeente's own setting, and rolling it to a working day would move a date nobody is owed. Every other date in that change goes through CaseDateNormaliser, which is why only this one line matches the patterns.

The set grew by one file, and by nothing else: lib/Service/TermijnTimerService.php now calls the engine's SlaCalculator::add(), which the ->add( pattern matches. It is the bridge, not a term, and its row says so.

The proposal counted five files referencing WorkingDayCalculator, and those five are all inside the 37. A sixth file references it at 16f00124a, lib/Service/Milestone/StalledCaseDetector.php, which does no date arithmetic of its own and so is not one of the 37. Two of the five, lib/Service/Kcc/SlaCalculator.php (since retired) and the calculator itself, have the verdict neither, which is why three rather than five statutory files reached a calendar before this change.

The table

Lines are the matching lines at 16f00124a. Reaches names what the file consults for the day a date lands on, after this change.

file	lines	verdict	reaches	reason
lib/BackgroundJob/AcknowledgementDispatchJob.php	136	neither		the retry counter for an acknowledgement that failed to send, attempt + 1 passed to IJobList::add(). It is one of the ->add( matches the pattern cannot anchor to a date type
lib/BackgroundJob/LinkCollectionToCaseJob.php	90	neither		queues the same dossier link again when the service account is missing, through IJobList::add(). One of the ->add( matches the pattern cannot anchor to a date type
lib/BackgroundJob/AdviceDeadlineJob.php	89	neither		a look-ahead window the daily scan uses to pick which advices to remind on, not a date anyone is held to
lib/Service/Setup/ExampleDataFragments.php	177	neither		example data dates relative to the moment the set is loaded (@today+2d), so a fresh install shows deadlines this week; fictional data, not a term anyone is held to
lib/BackgroundJob/DsoDeadlineJob.php	196, 205	statutory	WorkingDayCalculator	the Omgevingswet decision term; the day walk is already the calculator's
lib/Flow/DossiqAskPersonNode.php	648, 669	neither		a flow task due date and a node timeout in minutes, both process plumbing
lib/Service/Milestone/MilestoneStallTimer.php	154	business	WorkingDayCalculator	the day after a milestone's scheduled deadline, when its stall timer breaches (termijnbewaking-op-engine-timers 3.1). The deadline itself comes from StalledCaseDetector and MilestoneSchedule, which count working days; the +1 day only moves the breach to the first day the case is late, the day BottleneckDetectionJob reported it. A milestone is a house norm, not a term the Awb names
lib/Service/Pause/ChaseSchedule.php	105	business	WorkingDayCalculator	the interval between two reminders on a suspended term (pause-reason-with-chasing). The hersteltermijn ITSELF is statutory and DeadlinePauseService rolls it; a reminder inside that window is the gemeente's own schedule and nobody is in breach when one lands late. It still reaches the calendar, because a reason may declare countsWorkingDays and a reminder on a Sunday is a reminder nobody reads
lib/Portal/PortalSubmissionLedger.php	154	neither		claims a portal submission key with IMemcache::add(); the ttl is cache plumbing, not a date anyone is held to. One of the ->add( matches
lib/Service/Intake/CollectionLinkQueue.php	61	neither		puts the dossier link on the job list with IJobList::add(). One of the ->add( matches
lib/Service/Session/SessionRules.php	67, 84, 134	neither		the generic form of the hearing planner's rules (C12): the inspection floor is a minimum notice counted backwards from the session, and rolling it forward would shorten it; the attendance grace window is hours after the session start, process plumbing
lib/Service/Queue/UrgencyScorer.php	253	business	WorkingDayRoll	the business days until a deadline, for the urgency tier of the work queue. It is a display count, not a term anyone is held to, and it asks the administered calendar first (one-term-engine, REQ-OTE-04); the day shift only aligns its bounds with the Monday to Friday fallback walk
lib/Service/Queue/PersonalAgendaItemService.php	177	neither		the fortnight the personal queue looks ahead for items a person planned on their own calendar. It is a display window on a list, not a date anybody is held to, and moving it off a Saturday would hide a Saturday appointment from the person who booked it (one-personal-queue)
lib/Service/Queue/QueueFigures.php	65	neither		the coming week the team queue counts cases due within, for its "Deadline within 7 days" tile. A display window on a count, not a date anybody is held to; the days a case has waited are counted by DayCount
lib/Flow/DossiqRequestDecisionNode.php	615	neither		a node timeout in minutes
lib/Listener/AcknowledgementOnCreateListener.php	113	neither		queues the acknowledgement with attempt 1 through IJobList::add(), the same unanchored match. No date is computed here
lib/BackgroundJob/ReportGroupingJob.php	93	neither		requeues the report grouping of a case through IJobList::add() when no service account is set, the same unanchored match. No date is computed here
lib/Listener/ReportGroupingOnCreateListener.php	88	neither		queues the report grouping of a created case through IJobList::add(), the same unanchored match. No date is computed here
lib/Listener/CaseInheritedDeadlineListener.php	181	statutory	engine calendar	a deelzaak inherits the parent case type's term, so it inherits the term's end date
lib/Service/Actions/ScheduleReminderHandler.php	162, 167	neither		when a reminder background job runs
lib/Service/Archival/ArchivalNominationDeriver.php	259	neither		a retention period counted in years, where a weekend cannot move the answer
lib/Service/Beschikking/BezwaarTermijnScheduler.php	76, 77, 114	statutory	engine calendar	Awb 6:7, the six week bezwaartermijn and its reminder; line 114 is the archive trigger the day after and follows the rolled end
lib/Service/Beschikking/OpenRegisterArchivalAdapter.php	121, 153	neither		a retention period from the selectielijst, in years
lib/Service/Bezwaar/AdvisoryCommitteeService.php	178	business		the committee's own advice deadline, a house norm the Awb does not name
lib/Service/Bezwaar/HearingSchedulePlanner.php	106, 153	neither		the Awb 7:4 lid 2 inzage floor is a minimum notice counted backwards from the hearing; rolling an end date forward would shorten it
lib/Service/Bezwaar/HearingService.php	570	neither		a proposed hearing date two weeks out, which the planner then reschedules
lib/Service/CaseLifecycleService.php	516, 521	statutory	engine calendar	extends a case end date by the case type's period, which is the term a handler is judged on
lib/Service/CaseTermsService.php	249	statutory	engine calendar	binds the planned end, the internal target, the phase term and a case type's fixed closing date; every one of them is a date somebody is held to, and endAfter() is the single line that turns a day count into one
lib/Service/ComplaintAnalyticsService.php	247	neither		a six month reporting window
lib/Service/Termijn/TermDashboardFigures.php	83	neither		a seven day window on the deadline dashboard: which running terms end this week. It compares against each term's own endDateCurrent, which the engine already rolled; the quarter it reports on is a reporting window
lib/Service/ComplaintService.php	408	statutory	WorkingDayCalculator	Awb 9:11 klachttermijn in weeks; the service already consults the calculator for working days
lib/Service/DeadlineExtensionService.php	150	statutory	rollTermEndFor	an extension named in days (Woo art. 4.4 lid 2) asks for the current end plus those days; the asked-for date then goes through the same Algemene termijnenwet roll as every extension (one-term-engine)
lib/Service/DeadlinePauseService.php	93, 172	statutory	engine calendar	Awb 4:5 and 4:15: the credited suspension and the unused remainder both move endDateCurrent
lib/Service/DemoCaseloadReport.php	86	neither		a three day horizon in a demo report
lib/Service/DemoCaseloadSeedDataService.php	343	neither		demo seed data
lib/Service/Doorlooptijd/CaseEnricher.php	233	business	engine calendar	the dashboard's derived expected end; it mirrors a statutory term, so it rolls with it or it contradicts it on screen
lib/Service/Doorlooptijd/DeadlineComplianceCalculator.php	168	neither		month buckets for a compliance trend
lib/Service/DsoCaseService.php	310	statutory	WorkingDayCalculator	the Omgevingswet term; the day walk is already the calculator's
lib/Service/Money/PayoutService.php	133	statutory	engine calendar	Awb 4:17: paymentDateLatest is the date the dwangsom payment is late after
lib/Service/Kcc/CallbackRetrySchedule.php	71	neither		the wait before the next callback attempt, 15 minutes doubling to a day. It replaced Kcc/SlaCalculator.php (retired by termijnbewaking-op-engine-timers 4.1), whose channel SLAs nothing read; a retry wait is not a deadline and has no calendar
lib/Service/Money/AccrualNoticeService.php	188	statutory	engine calendar	Awb 4:17: the grace period whose end opens the dwangsom window
lib/Service/ProcessMining/ThroughputTrendCalculator.php	109	neither		weekly buckets for a throughput trend
lib/Service/ProcessMiningService.php	93, 96	neither		a twelve month reporting window
lib/Service/Recycle/RetentionClocks.php	144	neither		a lawful-purpose retention counted in months (AVG art. 5.1e), where a weekend cannot move the answer; the same verdict ArchivalNominationDeriver carries for the Archiefwet side
lib/Service/Import/CaseRecordImport.php	311-312	neither		converts the case type's declared ISO extension period (P14D) into a number of days, measured from a fixed day, to hand to the term carry-over. No date anyone is held to is computed here: the extended end is the carried source term's own, and the term engine rolls it (case-record-import, REQ-CRI-002)
lib/Service/Lifecycle/SilenceCloseService.php	131	neither		an ADMINISTERED period of silence a case type declares, after which the product closes the case, and the date it announces. Not a term: nothing in the Awb counts sixty days of nobody answering, the number is a gemeente's own setting, and a weekend cannot move an answer to "has anything happened". Same verdict as RetentionClocks for the same reason
lib/Service/QuickActionService.php	158	statutory	engine calendar	Awb 9:11: the six week klacht decision term, written on intake from the KCC
lib/Service/Status/StatusDwellService.php	135	business	WorkingDayCalculator	how long a case has sat in one status, a service level and never a term. The BREACH is the engine's: StatusDwellTimer arms it in the engine's own businessDays unit over the calendar the organisation administers. The count held on the case is the local calculator's, because the engine exposes projection and no count between two dates, so the two can differ by a day on a custom calendar. Closing that needs a count operation in openregister working-calendar-admin
lib/Service/Remedy/RemedyLodging.php	195	statutory	engine calendar	Awb 6:7 and 6:8, the term a remedy is lodged within, counted from the day the decision was made known; the end rolls to the next working day (Algemene termijnenwet art. 1) before a lodging is judged timely
lib/Service/Stuf/StufOutboundTransport.php	298	neither		not date arithmetic: IJobList::add() matched the ->add( pattern
lib/Service/Subsidie/BeschikkingService.php	82	statutory	engine calendar	the bezwaartermijn of a subsidy beschikking
lib/Service/Subsidie/BewijsstukService.php	136	neither		a record retention period in years
lib/Service/Subsidie/SubsidieService.php	151	statutory	engine calendar	the Awb decision term of a subsidy application
lib/Service/Subsidie/TerugvorderingService.php	88, 101	statutory	engine calendar	the bezwaartermijn and the payment term of a clawback decision
lib/Service/Subsidie/TussenrapportageService.php	99	statutory	engine calendar	the assessment term of an interim report, the date the applicant is answered by
lib/Service/TermijnNotificationService.php	97	neither		not date arithmetic: IJobList::add() matched the ->add( pattern
lib/Service/Term/FirstResponseOutcome.php	243	business	WorkingDayCalculator	the overrun on a first-response term (term-configuration-beyond-the-case-type). The +1 day is not a term end: it is where the count of days we were late STARTS, because the day we promised by is not a day we were late. The counting itself is the calculator's, so this file keeps no holiday list of its own. It moves to the engine calendar when one answers "how many working days between these two dates"; WorkingDayRoll rolls a single date and cannot answer that yet
lib/Service/TermijnTimerService.php	481	neither	itself	not date arithmetic: the engine's SlaCalculator::add() matched the ->add( pattern. This file IS the bridge; it asks the engine for the roll and computes no date of its own
lib/Service/TermijnService.php	109	statutory	engine calendar	endDateCalculated. Taken by terms-on-the-engine-calendar: createTermijnInstance() routes through TermijnTimerService::rollTermEndFor(), the one call every other term site makes, so the stored date and the armed timer come from one computation
lib/Service/WOODeadlineService.php	101, 172	statutory	engine calendar	Woo art. 4.4: the decision term and its statutory extension
lib/Service/Custody/CaseTakeoverRequest.php	299	business		the answer period a handler has before a takeover request escalates. An internal service clock, not a term the applicant is owed, so it counts calendar days on purpose and reaches no calendar: the escalation is about how long the request has sat, and a weekend it sat through is time it sat
lib/Service/Term/DependentTermOffer.php	228	statutory	allowlisted	the end date a dependent-term offer PROPOSES, endDateCurrent + N days, which a handler then approves. It is a statutory end date and it does not reach the calendar, so an offer can propose a Saturday. Owned by dependent-term-follows-predecessor; the one-line fix is to route it through TermijnTimerService::rollTermEndFor(), in that change rather than in a build fix
lib/Service/Termijn/WorkingDayRoll.php	196	neither	itself	not date arithmetic of its own: it ASKS the engine calendar (SlaCalculator::add() of zero business days, which matched the ->add( pattern) for the first working moment at or after an instant. This file is the calendar accessor the intake start uses; it holds no list, decides no policy, and since #2951 it does not read rollToWorkingDay either, because TermijnTimerService::rollEnabled() is the one place that decides
lib/Service/Termijn/TermEndRoll.php	221	neither	itself	not date arithmetic of its own: it ASKS the engine calendar (SlaCalculator::add() of zero business days, which matched the ->add( pattern) to roll a statutory end date off a weekend or a holiday. This is the Algemene termijnenwet roll, split out of TermijnTimerService so the admin screen can ask the roll whether a calendar answers without asking the timer service. The computation did not change when it moved, and the file it moved out of already carried this verdict
lib/Service/Termijn/TermDefinitions.php	247, 260	statutory	engine calendar	endDateCalculated, which is the row lib/Service/TermijnService.php carried at line 109 until the definitions got their own class. The computation did not change when it moved: TermijnService::createTermijnInstance() still routes the answer through TermijnTimerService::rollTermEndFor(), the one call every other term site makes, so the stored date and the armed timer come from one computation. Working-day definitions reach WorkingDayRoll from here, and a calendar that does not answer is logged at warning as a term that is SHORTER than it is owed
lib/Service/WorkingDayCalculator.php	170, 204	neither	itself	the calendar. It is the fallback the three sites use when the engine is absent, and the only holiday list dossiq is allowed to hold
lib/Woo/WooThroughputReport.php	164	neither		the throughput report adds one verdict to a per-reviewer, per-day tally through its own add() method. It counts work done on a day; no term is computed and nobody is held to a date
lib/Service/Term/ApplicantTermNote.php	256	neither		not date arithmetic: it parses the case type's extensionPeriod (ISO 8601) into a DateInterval only to say the period in words ("twee weken") in the sentence the applicant reads. No date is computed; the day the decision is due is copied from the case deadline the term engine keeps

Rows added after the reading

lib/BackgroundJob/AcknowledgementDispatchJob.php and lib/Listener/AcknowledgementOnCreateListener.php did not exist at 16f00124a and so are not in the 37 counted above. The change ontvangstbevestiging added them, and both are ->add( matches on IJobList, not on a date. They carry the verdict neither for the reason this file already names: two of the five patterns cannot be anchored to a date type. lib/BackgroundJob/ReportGroupingJob.php and lib/Listener/ReportGroupingOnCreateListener.php arrived later the same way, with ai-features-on-the-case-consume-hermiq, and carry the same verdict for the same reason. The counts below describe the reading, not the table.

lib/Service/Termijn/TermDefinitions.php and lib/Service/Termijn/TermEndRoll.php are the third and the fourth. Neither existed at 16f00124a: the roll moved out of lib/Service/TermijnTimerService.php and the definitions out of lib/Service/TermijnService.php, both when those classes went over their complexity ceiling. Each row carries the verdict the file it left already carried, because each call is the same call.

What the table is not

It is not a defect list. Twenty of the 37 have the verdict neither, and for each of them the reason is the point: saying once, in writing, that a throughput bucket does not need a working day roll is what stops the next reader running the same grep and reaching the same uncertainty.

Two rows deserve their own sentence.

• lib/Service/Bezwaar/HearingSchedulePlanner.php looks statutory and is not, in the sense this audit means. Awb 7:4 lid 2 gives a minimum of seven days between the inzage and the hearing. Algemene termijnenwet art. 1 lengthens a term by moving its end forward; applied to a floor counted backwards it would shorten the citizen's inzage, which is the opposite of what the Awt is for. The floor stays raw, deliberately.
• lib/Service/TermijnService.php is the one statutory file this change does not fix. It is the file terms-on-the-engine-calendar names as its motivating defect, and taking it here would edit another lane's open change. It is allowlisted with that change as its owner.