HTML Guide for time

The boolean required attribute can only be used with certain types of inputs. Check the input type is one of the allowed.

The required attribute, if present, indicates that the user must specify a value for the input before the owning form can be submitted.

The value used in the datetime attribute is not in a valid format.

The <time> HTML element represents a specific period in time. It may include the datetime attribute to translate dates into machine-readable format, allowing for better search engine results or custom features such as reminders.

The <time> HTML element represents a specific period in time, which can be taken from the datetime attribute or from the text contents of the element.

In both cases, the time or datetime must be in a valid format, for example:

a valid year string

2011

a valid month string

2011-11

a valid date string

2011-11-18

a valid yearless date string

11-18

a valid week string

2011-W47

a valid time string

14:54

14:54:39

14:54:39.929

a valid local date and time string

2011-11-18T14:54:39.929

2011-11-18 14:54:39.929

a valid global date and time string

2011-11-18T14:54:39.929Z

2011-11-18T14:54:39.929-0400

2011-11-18T14:54:39.929-04:00

2011-11-18 14:54:39.929Z

2011-11-18 14:54:39.929-0400

2011-11-18 14:54:39.929-04:00

a valid duration string

PT4H18M3S

For example:

<p>
  The event will take place on <time datetime="2025-03-20T13:00">March 20, 2025</time>.
</p>