dopecalc

Time Zone Converter

Convert a time from one UTC offset to another. Automatically adjusts the date if the conversion crosses midnight.

About this Calculator

Convert a time from one UTC offset to another. Automatically adjusts the date if the conversion crosses midnight.

Formula & Calculations

Formula

Converted time (minutes) = (Input hours * 60 + Input minutes) + (Target UTC offset - Source UTC offset) * 60
Where:
  • HH=Hour in 24-hour format (0–23)
  • MM=Minutes (0–59)
  • UTC offset=Difference from UTC in hours (e.g. +5:30, -8)

Assumptions

  • All time zone offsets are referenced against UTC.
  • The input time is treated as a local clock time in the source time zone.
  • Crossing midnight adjusts the date by ±1 day.

Calculation Examples

Example 1

Inputs:14:00 UTC-5 (New York) to UTC+1 (London)
Result:20:00 (same day)

The difference is +6 hours (1 - (-5) = 6), so 14:00 + 6 = 20:00.

Example 2

Inputs:23:00 UTC-8 (Los Angeles) to UTC+9 (Tokyo)
Result:16:00 (next day)

The difference is +17 hours. 23:00 + 17 = 40:00, which wraps to 16:00 the next day.

Frequently Asked Questions

Does this account for Daylight Saving Time?

This calculator works with fixed UTC offsets. For DST-aware conversions, select the correct offset for the time of year you are converting.

What time zone should I select for UTC?

Select 'UTC+00:00' for Coordinated Universal Time. This is the baseline reference for all other offsets.