Lumara Time

Business Days Calculator

Custom work weeks and holiday lists.

  • Free
  • No signup
  • No login

Inputs

What do you want to do?
Working weekdays
Add or subtract (add mode)

Result

How this tool works

Enter a start date and time, choose Add or Subtract, and fill in any combination of days, hours, minutes and seconds.

The calculation is pure calendar arithmetic with no time zone. Leap days and month lengths are handled automatically.

Time-zone rules come from the IANA database in your browser. This server uses database version 2026.5. If governments changed a rule very recently, the two can briefly disagree, so confirm important meetings with participants.

Frequently asked questions

Does it account for daylight saving?

No. It has no time zone, so every day is exactly 24 hours. Use the Duration Calculator to measure real elapsed time inside a time zone.

What range of dates is supported?

Results must fall between the years 1900 and 2200.

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