Date differences, weekdays and time zones
Three tools in one: a date difference with business days, a date calculator for adding or subtracting durations, and a time-zone converter that applies the daylight-saving rules of the target date.
How to use it
- Pick a card: difference, add/subtract, or time zones.
- Enter the dates (and zones where relevant).
- Results update instantly; business days count Mon-Fri only.
Limits & formats
Business days are Mon-Fri only, counted inclusively (both endpoint dates count) — public holidays are not supported in this first version. Daylight-saving transitions are handled for the specific date: skipped local times (spring-forward) are rejected with an explanation, and repeated times (fall-back) let you pick the earlier or later instance with its UTC offset shown. Leap years are handled by the calendar.
Privacy
Everything is computed locally in this browser tab; nothing is sent or stored.
Related tools
More tools are on the way.
Feedback on this tool
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