Maintenance Window Fit
Check whether dependent maintenance tasks and a buffer fit allowed outage windows. Compare elapsed time, local blackouts and daylight-saving changes.
Starts with an editable example. Replace the dates and rules with your own.
Your calculation
Ready when you are
Choose your dates.
Select your counting rules and calculate.
Calculation details
| Step | Value |
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How to use this calculator
Choose the time zone and repeated-time rule. Enter allowed start/end windows, local blackout dates, task durations in minutes and predecessor IDs.
Each window is tested independently against the critical-path duration plus one final buffer. Independent tasks may run in parallel. A blackout on any occupied local date disqualifies the window; its ending instant is exclusive.
A worked example
Backup, update and verification taking 30, 45 and 15 dependent minutes need 90 minutes. With a 15-minute buffer, a two-hour window fits with 15 minutes spare; one hour does not.
Will this execute maintenance or reserve resources?
No. Calendar exports mark possible windows only. Review resource availability, rollback needs and approval requirements before using one.
Which calendar and years are supported?
Use Gregorian dates from 1900 through 2100, with results in that range. Daily attendance, office, coverage and chore plans allow up to 366 dates; school cycles, course plans and milestones allow up to 731. Dependency and historical workday calculations scan at most 3,661 dates. Class-session searches allow 366 dates and 200 sessions. Time-zone tools use browser IANA rules and require a choice when local times repeat. Dates and policy rules are entered manually; no employer, retailer, school or local weather policy is inferred. Copy, CSV and printing include the calculation rules; calendar exports appear when the result contains dated events.
What happens to my dates?
Calculations run on your device. Saving a calculation is optional and keeps it in this browser. A setup link contains the dates and settings you entered; anyone with the link can read them. Use one tab per saved calculator. Clear saved data from Privacy & settings.