GetSystemTimeAdjustmentPrecise function (sysinfoapi.h)

Determines whether the system is applying periodic, programmed time adjustments to its time-of-day clock, and obtains the value and period of any such adjustments.


BOOL GetSystemTimeAdjustmentPrecise(
  [out] PDWORD64 lpTimeAdjustment,
  [out] PDWORD64 lpTimeIncrement,
  [out] PBOOL    lpTimeAdjustmentDisabled


[out] lpTimeAdjustment

Returns the adjusted clock update frequency.

[out] lpTimeIncrement

Returns the clock update frequency.

[out] lpTimeAdjustmentDisabled

Returns an indicator which specifies whether the time adjustment is enabled.

A value of TRUE indicates that periodic adjustment is disabled. In this case, the system may attempt to keep the time-of-day clock in sync using its own internal mechanisms. This may cause time-of-day to periodically jump to the "correct time."

A value of FALSE indicates that periodic, programmed time adjustment is being used to serialize time-of-day, and the system will not interfere or attempt to synchronize time-of-day on its own.

Return value

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. To get extended error information, call GetLastError.


This function is used in algorithms that synchronize the time-of-day with another time source, using a programmed clock adjustment. To do this, the system computes the adjusted clock update frequency, and then this function allows the caller to obtain that value.


For a complete code sample on how to enable system-time privileges, adjust the system clock, and display clock values, see SetSystemTimeAdjustmentPrecise.



Minimum supported client Windows 10 [desktop apps only]
Minimum supported server Windows Server 2016 [desktop apps only]
Target Platform Windows
Header sysinfoapi.h
Library Mincore.lib
DLL Api-ms-win-core-version-l1-2-3.dll

See also