LocalTime — GraphQL Custom Scalar

Author – apollographql

Date - 2025-12-04

License and Copyright

1Overview

This scalar represents a local date and time, without any reference to a time zone.

Using RFC 3339 format, a LocalTime is represented as partial-time:

time-hour       = 2DIGIT  ; 00-23
time-minute     = 2DIGIT  ; 00-59
time-second     = 2DIGIT  ; 00-58, 00-59, 00-60 based on leap second
                         ; rules
time-secfrac    = "." 1*9DIGIT

partial-time    = time-hour ":" time-minute ":" time-second
                 [time-secfrac]

Fractional second precision:

RFC 3339 allows representing fractional seconds with arbitrary precision, which is impractical in most programming languages.

For convenience, this specification enforces nanosecond precision with at most nine digits.

Note JavaScript Date only has millisecond precision. Use LocalTime with care if you are using it in applications that require precise times.

2Recommended Name

The recommended name is LocalTime.

3GraphQL input coercion

The input must be a GraphQL StringValue matching the description above.

All other values must raise an error.

4JSON input coercion

The input must be a JSON string matching the description above.

All other values must raise an error.

5JSON result coercion

The result must be a JSON string matching the description above.

6Examples

Because GraphQL StringValue and JSON string are so similar, the first column in the table below may be understood as either a GraphQL StringValue or a JSON string.

Value	Description
`23:59:59`	A valid time.
`23:59:59.123`	A time with a fractional second.
`23:59:59.123000`	Trailing zeroes are valid.
`23:59:59.123456789`	Nanosecond precision.

These are invalid examples:

Value	Why is it invalid
`24:59:59`	`24` is not a valid `time-hour`.
`23:60:59`	`60` is not a valid `time-minute`.
`23:59:61`	`61` is not a valid `time-second`.
`23:59:59.123456789123`	Seconds exceed nanosecond precision.
`23:59:59.1234567890`	More than nine digits for `sec-frac`.
`15:20:15-07:00`	Time offsets are not allowed.