CreateDateTimeFromMilliseconds

Creates a DateTime from milliseconds since 1970, 00:00:00 GMT. This reference point — midnight on January 1, 1970 UTC — is known as the Unix epoch, and is a standard way many systems and APIs represent timestamps as a single large number rather than a formatted date string.

Understanding Unix Epoch Timestamps

The Unix epoch counts every millisecond that has passed since 1970-01-01T00:00:00 GMT. This is how many modern APIs, databases, and logging systems store timestamps internally — as a single large integer — because it avoids ambiguity around date formats, timezones, and locale differences.

The CenturyIncluded Property

Some legacy or proprietary systems prepend a single digit to their epoch millisecond values as a century marker (typically 1 for the 21st century). Setting CenturyIncluded to true tells the action to strip that leading digit before performing the conversion, ensuring the result is correct.

If your source value has 14 digits and CenturyIncluded is left as false, the result will be an incorrect date far in the future — so it's important to know whether your source system uses this convention.

Typical Use Case

Processing timestamps from a REST API or JSON payload

Many modern APIs return timestamps as epoch milliseconds. For example, an order management system might return:

"order_timestamp": 1718445900000

Rather than parsing a date string, you can feed this value directly into CreateDateTimeFromMilliseconds to produce a proper DateTime, which can then be used downstream in actions like CalculateDuration, AddDateTimeWithFields, or CreateStringFromDateTime to format it for an outbound EDI document or target system.

Notes

• If DateTimeMilliseconds is null, the action returns null — include a null check in your ruleset if the source value may be absent.
• The conversion is performed in UTC (GMT). If your integration requires local time, apply a timezone offset using AddDateTimeWithFields after conversion.
• For timestamps provided as a formatted date string (e.g. "2024-06-15"), use CreateDateTimeFromString instead. For assembling a DateTime from discrete numeric fields, use CreateDateTime.

Related Actions

• CreateDateTime: build a DateTime from individual year, month, day, hour, minute, and second values.
• CreateDateTimeFromString: convert a formatted date/time string into a DateTime.
• AddDateTimeWithFields: shift the resulting DateTime by a specified interval (e.g. add hours to adjust for timezone).
• CreateStringFromDateTime: format the resulting DateTime as a string for output.