Pick the tool by the units you need
Date questions look similar and fail in different ways. Date & Time Ops is the Tools.Town cluster for choosing the right calculator — calendar offsets, elapsed intervals, overnight clock duration, and Unix/ISO conversion — free and in-browser.
Write the question with units first: “90 calendar days after…”, “8 hours overnight…”, or “Unix seconds to ISO…”. The units pick the tool.
Confused about formats? Read ISO 8601 vs Unix Timestamps before pasting API values into code.
The Date & Time Ops workflow
Decide units
Calendar days, business days, HH:MM, or Unix/ISO instants.
Measure or offset
Difference between two dates, or add/subtract from one date.
Clock spans
Overnight and multi-segment timesheets use duration tools.
Machine time
Convert Unix ↔ human dates; keep seconds vs ms explicit.
Start here by persona
Ops / support
SLA deadlines → Business Days Calculator + calendar-vs-business guide.
Timesheets
Overnight shifts → Time Duration (spans midnight / multi-segment).
Developers
API timestamps → Unix Timestamp to Date + ISO vs Unix guide.
PM / planning
Milestones → Add Days to Date or Date Calculator.
Remote teams
Meeting walls → Timezone Converter / World Clock.
Analysts
How long between dates → Date Difference or Days Between Dates.
Tools in this cluster
| Tool | Best for |
|---|---|
| Date Calculator | Full control — add/subtract Y/M/W/D |
| Add Days to Date | Intent landing — Add + days preset |
| Subtract Days from Date | Intent landing — Subtract preset |
| Days Until Date | Today → target day count preset |
| Date Difference | Calendar split: days/weeks/months/years |
| Days Between Dates | Simple day count |
| Business Days Calculator | Skip weekends (+ custom holidays) |
| Time Duration Calculator | Hours/minutes between clock times |
| Overnight Time Duration | Night shift / crosses-midnight preset |
| Epoch Converter | Unix ↔ date (full control) |
| Unix Timestamp to Date | Timestamp → date preset |
| Date to Unix Timestamp | Date → timestamp preset |
| Timezone Converter | Wall times across zones |
| Countdown Timer | Live remaining time to a target |
Featured use cases
Browse all workflows on the Use Cases index.
- Calculate an SLA deadline in business days
- Timesheet hours for an overnight shift
- Days until a product launch
- Decode API created_at Unix timestamps
- Project a milestone +90 calendar days
- Schedule a meeting across timezones
Guides & comparisons
Browse evergreen concepts on Guides and side-by-sides on Comparisons.
Learn the concepts
- Calendar Days vs Business Days
- Elapsed Time vs Clock Duration vs Date Difference
- ISO 8601 vs Unix Timestamps
- Timezone vs UTC vs Local Time