Dates & time

Time Zone Converter

Convert a clock time between explicitly entered fixed UTC offsets, including fractional-hour offsets and crossings into another day. This is not a city-time-zone or daylight-saving converter.

Explicit formulas and worked examples
Check your inputs, then calculate
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Check the stated input format, calculation convention and limits before using the result.

Check the example inputs, then calculate. Your values stay in this browser.

Offsets range from −12 to +14 hours with whole-minute precision.

Calculation notes

Understand the Time Zone Converter

Time Zone Converter validates source time, source utc offset hours, target utc offset hours before applying the displayed equation. Offsets range from −12 to +14 hours with whole-minute precision.

Formula and logic

What is the formula for the Time Zone Converter?

Time Zone Converter: target minutes = source minutes − source offset × 60 + target offset × 60. Input definitions: time = Source time; from = Source UTC offset hours; to = Target UTC offset hours. Use the selected convention throughout the calculation.

Worked example

How can I reproduce the Time Zone Converter example?

Time Zone Converter baseline input: Source time: 12:00; Source UTC offset hours: 0; Target UTC offset hours: 8. Output: Target time (fixed UTC offset) = 20:00; Day offset = 0. Substitute these values into the displayed equation to reproduce the result.

How to read the result

How should I interpret the Time Zone Converter result?

Read target time (fixed utc offset) with its stated unit and convention. The default example and the independent worked scenario use different inputs, so compare the assumptions before comparing the numbers.
Change one input at a time and use the equation to explain the result; do not mix unit, grade-scale, time-zone or rounding conventions across comparisons.

Limits and assumptions

What limits apply to the Time Zone Converter?

Offsets range from −12 to +14 hours with whole-minute precision.
Choose the offset actually in effect on the relevant date; cities are deliberately not used as fixed labels.

Content and calculation reviewed: 2026-10-11

Understand the calculation

How to use it and the math behind it

Read the complete explanation

Four steps to check your inputs and results

Convert a clock time between explicitly entered fixed UTC offsets, including fractional-hour offsets and crossings into another day. This is not a city-time-zone or daylight-saving converter.
Enter Source time, Source UTC offset hours, Target UTC offset hours in the stated format. Baseline values are for reproduction.
Check the output unit and convention: Read target time (fixed utc offset) with its stated unit and convention. The default example and the independent worked scenario use different inputs, so compare the assumptions before comparing the numbers.
Change one input and compare the result. Offsets range from −12 to +14 hours with whole-minute precision. Choose the offset actually in effect on the relevant date; cities are deliberately not used as fixed labels.