## How Does GetSystemTimeAdjustment Relate to Observed Time Increments?

Windows 7 Timing Functions: Clarifying the Usage of GetSystemTimeAdjustment

Question 1: Assumptions and Function Behavior

The assumption that querying the system time repeatedly using GetSystemTimeAsFileTime should result in either no change or changes in increments matching the value returned by GetSystemTimeAdjustment is correct. However, it's crucial to consider the system clock settings, as they can influence the observed behavior.

Question 2: Explanation of Results

The discrepancy in the reported time increment and the observed time updates is likely due to the influence of the multimedia timer interface, which can modify the system clock's behavior. The multimedia timer interface allows for customization of the clock's resolution and period, which in this case, is set to a smaller interval than the value returned by GetSystemTimeAdjustment.

Summary

• GetSystemTimeAdjustment provides information about time synchronization but does not control the clock's update period.
• NtQueryTimerResolution provides the actual time increment, which is potentially smaller than what is reported by GetSystemTimeAdjustment.
• The multimedia timer interface (timeBeginPeriod) can influence the time increment and cause discrepancies in the observed behavior.
• Frequent calls to timeBeginPeriod can significantly affect the system clock and should be used with caution.

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