About this Time Zone Offset Calculator
Time Zone Offset Calculator converts a wall-clock date/time between user-specified UTC offsets, including fractional-hour offsets.
Formula or method
UTC instant = stated local time − source UTC offset; target time = UTC instant + target UTC offset.
Example
12:00 at UTC+5 converted to UTC+0 becomes 07:00 UTC on the corresponding date.
Common uses
- Convert a meeting time between fixed UTC offsets.
- Check cross-date time changes.
- Work with half-hour or quarter-hour offsets.
How to use this tool
- Enter the values or text requested by the calculator.
- Choose units or options when the tool provides them.
- Select the calculation button and review the result.
- Use the formula, example and notes on this page to check whether the result fits your situation.
Important note
Numeric offsets do not automatically model named-zone daylight-saving rules; enter the offsets that apply for the date you are converting.
Frequently asked questions
Does it know daylight-saving rules?
No. Enter the actual source and target offsets that apply on the chosen date.
Can I enter UTC+5:30?
Yes. Enter 5.5 as the numeric offset.