DateTimeZone.FromFileTime

DateTimeZone

Converts a Windows file time to a datetimezone value in UTC.

Syntax

DateTimeZone.FromFileTime(fileTime as nullable number) as nullable datetimezone

Parameters

Name	Type	Required	Description
`fileTime`	`number`	Yes	A 64-bit integer representing the number of 100-nanosecond intervals since January 1, 1601 (UTC).

Return Value

datetimezone — A datetimezone value in UTC (+00:00) corresponding to the given Windows file time.

Remarks

DateTimeZone.FromFileTime converts a Windows FILETIME value — the number of 100-nanosecond intervals since 00:00:00 UTC on January 1, 1601 — into a datetimezone value with a +00:00 (UTC) offset. This differs from DateTime.FromFileTime, which converts to local time without timezone information. Use this function when you need to preserve the UTC context of timestamps from Windows APIs, Active Directory, or NTFS metadata.

If the input is null, the function returns null.

Examples

Example 1: Convert Active Directory lastLogon to UTC datetimezone

Table.AddColumn(
    Table.SelectColumns(
        Table.FirstN(ActiveDirectory, 4),
        {"UserID", "LastLogonFileTime"}
    ),
    "LastLogonUTC",
    each DateTimeZone.FromFileTime([LastLogonFileTime]),
    type datetimezone
)

Result

	UserID	LastLogonFileTime	LastLogonUTC
1	U001	133,500,000,000,000,000	1/15/2024 2:20:00 PM
2	U002	133,550,000,000,000,000	3/6/2024 1:33:20 PM

Example 2: Convert a known file time to UTC datetimezone

#table(
    type table [FileTime = number, UTCDateTime = datetimezone],
    {{132000000000000000, DateTimeZone.FromFileTime(132000000000000000)}}
)