ToFileTimeUtc Method

DateTime::ToFileTimeUtc Method ()


Converts the value of the current DateTime object to a Windows file time.

Namespace:   System
Assembly:  mscorlib (in mscorlib.dll)

long long ToFileTimeUtc()

Return Value

Type: System::Int64

The value of the current DateTime object expressed as a Windows file time.

Exception Condition

The resulting file time would represent a date and time before 12:00 midnight January 1, 1601 C.E. UTC.

A Windows file time is a 64-bit value that represents the number of 100-nanosecond intervals that have elapsed since 12:00 midnight, January 1, 1601 A.D. (C.E.) Coordinated Universal Time (UTC). Windows uses a file time to record when an application creates, accesses, or writes to a file.

The ToFileTimeUtc method uses the Kind property to determine whether the current DateTime object is a local time, a UTC time, or an unspecified kind of time which is treated as a UTC time. If it is a local time, it converts the time to UTC before performing the conversion to a Windows file time.

Notes to Callers:

The ToFileTimeUtc method is sometimes used to convert a local time to UTC, and subsequently to restore it by calling the FromFileTimeUtc method followed by the ToLocalTime method. However, if the original time represents an invalid time in the local time zone, the two local time values will not be equal. For additional information, see the ToLocalTime method.

Universal Windows Platform
Available since 4.5
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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