How to get current time in FILETIME format?

Question

How can I use PowerShell on Windows to get the current time in the Windows FILETIME format?

Something like this answer about Linux except for Windows, using the Windows FILETIME format (64-bit value representing the number of 100-nanosecond intervals since January 1, 1601 UTC), and preferably something simple like the aforementioned answer.

Answer 1

# Returns a FILETIME timestamp representing the current UTC timestamp,
# i.e. a [long] value that is the number of 100-nanosecond intervals 
# since midnight 1 Jan 1601, UTC.
[datetime]::UtcNow.ToFileTime()

^{Alternatives: [dateime]::Now.ToFileTimeUtc() or [datetimeoffset]::Now.ToFileTime()}

To convert such a FILETIME value back to a [datetime] instance:

# Creates a [datetime] instance expressed as a *local* timestamp.
[datetime]::FromFileTime(
  [datetime]::UtcNow.ToFileTime()
)

Note: The above yields a local [datetime] instance (its .Kind property is Local). Append .ToUniversalTime() to get a UTC instance (where .Kind is Utc).

Or, use [datetime]::FromFileTimeUtc() (note the Utc suffix), which directly yields a UTC [datetime] instance:

# Creates a [datetime] instance expressed as a *UTC* timestamp.
[datetime]::FromFileTimeUtc(
  [datetime]::UtcNow.ToFileTime()
)

Alternatively, use [datetimeoffset]::FromFileTime() to obtain an unambiguous timestamp, which can be used as-is or converted to a local (.LocalDateTime) or a UTC (.UtcDateTime) [datetime] instance, as needed.

# A [datetimeoffset] instance unambiguously represents a point in time.
# Use its .LocalDataTime / .UtcDateTime properties to get
# local / UTC [datetime] instances.
[datetimeoffset]::FromFileTime(
  [datetime]::Now.ToFileTimeUtc()
)