Timezone / Date Math Calculator
Convert times across time zones, plan meetings, calculate business-day offsets and SLA deadlines, parse ISO durations, and inspect date ranges — locally in your browser.
- Translate release, incident, or meeting times across multiple IANA time zones at once.
- Apply day, week, month, hour, minute, second, or business-day offsets — with month-end and DST-aware warnings.
- Compute SLA deadlines using business hours, weekends, and a custom holiday list.
- Parse ISO 8601 / friendly durations, inspect date ranges, and export Markdown / CSV / JSON / .ics.
- Share results: Generate a secure link to share your current input and results with teammates — nothing is uploaded to any server.
One tool for wall-clock conversions, multi-zone planning, business-day math, SLA deadlines, and ISO duration parsing.
Timezone conversion
2026-04-04 15:30 are interpreted in the source time zone you provide. Trailing Z or an offset like +05:30 overrides the source zone.
Multi-zone comparison
| Time zone | Date | Time | Offset | Abbr | Status | Day diff |
|---|
Day diff is relative to the source zone. Status uses the business hours above and weekend rules from Business / SLA.
Date math
Calendar mode preserves the wall-clock time across DST. Fixed mode adds an exact number of seconds (may shift the wall clock by an hour through DST).
Business calendar
SLA rules vary by organization. Holidays are local-only to your browser.
SLA / deadline calculator
Duration parsing
Date range inspector
Calendar / release window
External calendar links open the provider with your event text in the URL. Avoid sensitive details unless you trust the recipient.
Formats / snippets
Built from the most recent Convert / Date math result. Distinguish local, UTC, and zoned time before pasting into code.
Next steps
Suggestions appear after you run a calculation.