The <time> CSS data type represents a time value expressed in seconds or milliseconds. It is used in animation, transition, and related properties.


The <time> data type consists of a​ ​​​​​​<number> followed by one of the units listed below. Optionally, it may be preceded by a single + or - sign. As with all dimensions, there is no space between the unit literal and the number.

Note: Although the number 0 is always the same regardless of unit, the unit may not be omitted. In other words, 0 is invalid and does not represent 0s or 0ms.


Represents a time in seconds. Examples: 0s, 1.5s, -60s.
Represents a time in milliseconds. Examples: 0ms, 150.25ms, -60000ms.

Note: Conversion between s and ms follows the logical 1s = 1000ms.


Valid times

12s         Positive integer
-456ms      Negative integer
4.3ms       Non-integer
14mS        The unit is case-insensitive, although capital letters are not recommended.
+0s         Zero with a leading + and a unit
-0ms        Zero with a leading - and a unit

Invalid times

0           Although unitless zero is allowed for <length>s, it's invalid for <time>s.
12.0        This is a <number>, not a <time>, because it's missing a unit.
7 ms        No space is allowed between the number and the unit.


Specification Status Comment
CSS Values and Units Module Level 3
The definition of '<time>' in that specification.
Candidate Recommendation Normative definition of s and ms.
CSS Level 2 (Revision 1)
The definition of '<time>' in that specification.
Recommendation Informal definition of s and ms.

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support Yes ?49 Yes Yes
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support Yes Yes ? ? Yes Yes Yes

Document Tags and Contributors

 Last updated by: fscholz,