Wholehour

Wholehour is a term used in timekeeping and software contexts to describe a time interval that begins at the start of a calendar hour and lasts for one hour. It is not part of an official time standard; its usage is informal and varies by domain. In most uses, a wholehour timestamp has minutes and seconds equal to zero, for example 2025-07-20T14:00:00Z.

A wholehour unit corresponds to 3600 seconds. In data processing, aligning timestamps to whole hours means flooring to the nearest hour or shifting to the start of the hour. There can be an important distinction between wholehour blocks and hourly timestamps that reflect the time of an event. Example: 14:37:02 rounded down to 14:00:00 defines the 14:00–15:00 interval.

Applications include billing and resource scheduling where charges or allocations are computed per wholehour block, and time-series databases that aggregate data by hour. In software, many libraries provide functions to floor or truncate to the hour.

Variants and related concepts include rounding to the nearest hour, rounding up to the next hour, and calendar alignment. In computing, wholehour aligns with the start of the hour, typically when times are normalized to a common time zone.

See also: time rounding, hour, time interval, cron, time-series aggregation, floor function.