Date and time

Dates and times clarify when an event occurred. The way they are formatted should be informative, not disruptive. While users can choose a preferred date and time format, there are occasions when we default to a specified format instead.

Date and time options

Absolute format

The absolute format clarifies the precise date and time that something occurred.

Absolute date and time information can be localized to display a user's local date and time or follow the ISO 8601 format. See the Guidelines section for more information about when dates should be localized, and when they should be shown in ISO 8601.

  • Localized dates display as Jan 03, 2021 or are shortened to Jan 03 when space is tight. Always show the full date and time data, along with the timezone, in a tooltip if the date is shortened. Both dateStyle and timeStyle should be set to medium.
  • ISO 8601 format is displayed YYYY-MM-DD. Time can also be appended to the end of the date if necessary as HH:MM:SS

Relative format

The relative format communicates the approximate amount of time that has passed since an event occurred; whether that event occurred XX minute(s), hour(s), day(s), week(s), month(s), or year(s) ago. For example, it is used to communicate that an issue was opened 1 minute ago or 10 months ago.

When using the relative format, always display the absolute time in a tooltip following the Guidelines below.


Which format to use when

  • Display date and time information in the absolute format unless users specify they want to use relative formatting instead.
  • If it's possible to detect the browser settings, display the localized time, for example Jan 03, 2021. Otherwise, fall back to displaying the date in ISO 8601: YYYY-MM-DD (time is optionally appended after the date, HH:MM:SS).
Flow chart date and time format decision tree; read the guidelines to learn how to use absolute and relative time and date.


In certain scenarios, the date and time are displayed in a specific format and the user's preference is overridden.

Use absolute format when:

  • Users need specific dates and/or times for technical, security, or legal reasons. For example, in an audit log, a tax form, or a security alert.
  • Users would need to convert relative time to absolute time in order to complete a task.
  • A range of time is displayed, for example in a date picker.

Use relative format when:

  • Content is updated frequently and specifics are not critical. For example, a live newsfeed or notification.

Adding timezone data

In situations where timezone context is important, for example in alerts or incidents, append the timezone information to the end of the date and time.

Last updated at: