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

Pick two zones and a date. The tool reads each zone's UTC offset for that exact moment and subtracts them.

It then lists the clock changes in that year for both zones and shows how long each version of the gap lasts.

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

Is the time difference between two cities always the same?

No. If either city changes its clocks, the gap changes, and when two cities change on different dates the gap can differ for a few weeks.

Which sign means ahead?

A positive value means the second zone is ahead of the first.

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