Technical and media time

Leap-Second and TAI-UTC Converter

Apply an entered TAI−UTC offset to a UTC timestamp.

PrivacyRuns in your browser
OutputTechnical console
CostFree to use
Technical console

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Purpose and scope

What this technical calculator produces

Apply an entered TAI−UTC offset to a UTC timestamp.

The Leap-Second and TAI-UTC Converter generates a readable value from UTC timestamp and TAI−UTC seconds; Retain TAI−UTC seconds beside the copied output.

InterfaceTechnical console
OutputReadable and copyable values

Instructions

How to use this calculator

Enter UTC timestamp and TAI−UTC seconds from the Leap-Second and TAI-UTC Converter working data, then check TAI−UTC seconds with the required technical convention.

  1. Enter UTC timestamp and TAI−UTC seconds exactly as supplied by the working data.
  2. Generate the Leap-Second and TAI-UTC Converter conversion and check TAI−UTC seconds with the copyable output.
  3. Check the Leap-Second and TAI-UTC Converter reference with the TAI−UTC seconds definition or convention.

Calculation

Method used

The entered whole-second offset is added to UTC to produce the corresponding TAI label.

TAI label = UTC timestamp + entered TAI−UTC whole-second offset.

The Leap-Second and TAI-UTC Converter relates UTC timestamp and TAI−UTC seconds to the converted value; retain the TAI−UTC seconds precision or unit convention.

Calculation method last reviewed: June 21, 2026.

Verification

References

Reference and calculation method reviewed: June 21, 2026.

Worked scenario

Example calculation

Example: Adding thirty-seven seconds to a current UTC label produces the corresponding simplified TAI label.

Check the Leap-Second and TAI-UTC Converter worked value with TAI−UTC seconds, then review its precision and format.

Interpretation

Validating the generated output

The arithmetic is only as accurate as the supplied offset for the historical or future date.

Review the Leap-Second and TAI-UTC Converter output against TAI−UTC seconds before sending its unit, epoch, or syntax elsewhere.

Boundaries

Important edge cases and limitations

Historical and future offsets must be supplied from a published leap-second table.

Revise the Leap-Second and TAI-UTC Converter convention when TAI−UTC seconds uses another epoch, precision, or syntax rule.

Input audit

Checklist for this calculation

  • Review the Leap-Second and TAI-UTC Converter unit or epoch in UTC timestamp and TAI−UTC seconds.
  • Check TAI−UTC seconds with the Leap-Second and TAI-UTC Converter copyable output.
  • Check the Leap-Second and TAI-UTC Converter reference with the TAI−UTC seconds date and use case.

Questions

Frequently asked questions

Why is the TAI−UTC offset not constant?

UTC inserts leap seconds while TAI is a continuous atomic time scale.

When should IERS: Bulletin C leap-second announcements be checked for the

Check IERS: Bulletin C leap-second announcements with TAI−UTC seconds whenever the Leap-Second and TAI-UTC Converter cutoff affects a decision. Retain its version or access date beside UTC timestamp.

What context should accompany UTC timestamp in the

UTC timestamp identifies the Leap-Second and TAI-UTC Converter source value, while TAI−UTC seconds specifies part of its output convention. Confirm both before copying the converted value.

Does TAI−UTC seconds alter every part of the leap-second and tai-utc converter result?

Run the Leap-Second and TAI-UTC Converter twice with the same UTC timestamp and a different TAI−UTC seconds. Compare both Leap-Second and TAI-UTC Converter output forms before adopting the new TAI−UTC seconds convention.