PT4H

PT4H is an ISO 8601 duration designator that specifies a time interval of four hours. The notation begins with P to indicate a period, then T to separate the date and time components. Because the value includes only time components, there are no days, months, or years in PT4H.

As a duration, PT4H represents four hours, which is equivalent to 240 minutes or 14,400 seconds. It is used to express lengths of time rather than a specific clock time. For example, PT4H can denote the length of a meeting, a timeout, or any other interval.

PT4H can be combined with other components to form longer durations, such as P1DT4H (one day and four hours) or P2DT4H30M (two days, four hours, and thirty minutes). Conversely, PT4H can be written explicitly as PT4H0M, which is equivalent.

In practice, PT4H appears in scheduling, data formats, and APIs that adopt ISO 8601 durations. It is considered a duration rather than a time of day, so it does not imply a specific start time unless used in conjunction with a separate timestamp.

Notes on parsing and usage: many programming languages and libraries provide ISO 8601 duration parsers, and PT4H is commonly accepted as a valid four-hour duration string. The format is widely understood in international standards for time intervals.