Date and time notation
How timestamps, offsets, and time zones interact when a date moves between systems.
Continue with Timestamp Converter, Timezone Converter, Date Difference Calculator · Reference
An instant is not a display format
An instant identifies a point on the timeline. An ISO 8601 string can include an offset such as +08:00 or the UTC marker Z; a local date-time without an offset is incomplete when it crosses a system boundary.
Make the unit explicit
- Document whether Unix values are seconds or milliseconds.
- Carry an offset or time-zone identifier when local wall time matters.
- Format for people only at the presentation boundary.
References
Related tools
- Timestamp ConverterConvert dates and times between common formats, Unix seconds or milliseconds, and UTC.
- Timezone ConverterConvert times between IANA timezones with DST handled.
- Date Difference CalculatorCalculate the exact duration between two dates and times.