fromTimestamp

fromTimestamp is a function or factory used in several programming environments to convert a numeric timestamp into a date-time value. It generalizes the idea of translating a raw epoch value into a language’s native date or time object.

The typical purpose of fromTimestamp is to take a point in time represented as a numeric value, usually counting seconds since the Unix epoch (January 1, 1970), and produce a date-time representation in a specific language. Many implementations also allow different units (seconds, milliseconds, or higher-precision units) and may provide a way to specify the target time zone or to request a UTC result. The exact return type depends on the API and language, but it is commonly a date-time object, a timestamped structure, or a string in a standardized format.

Because unit conventions and time-zone handling differ between ecosystems, correct usage is important. Misinterpreting units (for example, using milliseconds where seconds are expected) can lead to incorrect dates. Some variants support nanoseconds or customizable scales, and some return a time-zone aware value while others output a naive/UTC-based result.

Examples across languages illustrate the concept rather than a single standardized signature. In Python, a function analogous to fromTimestamp may construct a datetime from seconds since the epoch, with optional timezone parameters. In JavaScript and other ecosystems, libraries or language APIs provide similar conversions, often requiring units to be adjusted (such as multiplying by 1000 to convert seconds to milliseconds). In C# and Java, dedicated methods exist to create date-time values from Unix timestamps, typically with explicit handling of time zones.

See also: toTimestamp, Unix time, epoch, ISO 8601, time zone.