EnumDynamicTimeZoneInformation function (timezoneapi.h)

Article
12/06/2022

Enumerates DYNAMIC_TIME_ZONE_INFORMATION entries stored in the registry. This information is used to support time zones that experience annual boundary changes due to daylight saving time adjustments. Use the information returned by this function when calling GetDynamicTimeZoneInformationEffectiveYears to retrieve the specific range of years to pass to GetTimeZoneInformationForYear.

Syntax

DWORD EnumDynamicTimeZoneInformation(
  [in]  const DWORD                    dwIndex,
  [out] PDYNAMIC_TIME_ZONE_INFORMATION lpTimeZoneInformation
);

Parameters

[in] dwIndex

Index value that represents the location of a DYNAMIC_TIME_ZONE_INFORMATION entry.

[out] lpTimeZoneInformation

Specifies settings for a time zone and dynamic daylight saving time.

Return value

This function returns DWORD. Possible return values include:

Value	Description
ERROR_SUCCESS	The operation succeeded.
ERROR_NO_MORE_ITEMS	No more data is available for the given index.
ERROR_INVALID_PARAMETER	A parameter is invalid.
Any other value	The operation failed.

Remarks

The following example demonstrates looping through the potential timezones until ERROR_NO_MORE_ITEMS is returned, indicating that there are no more time zone entries in the registry.

std::vector<DYNAMIC_TIME_ZONE_INFORMATION> possibleTimezones;
DYNAMIC_TIME_ZONE_INFORMATION dynamicTimezone = {};
DWORD dwResult = 0;
DWORD i = 0;

do
{
    dwResult = EnumDynamicTimeZoneInformation(i++, &dynamicTimezone);
    if (dwResult == ERROR_SUCCESS)
    {
        possibleTimezones.push_back(dynamicTimezone);
    }
}
while (dwResult != ERROR_NO_MORE_ITEMS);

Requirements

Requirement	Value
Minimum supported client	Windows 8 [desktop apps \| UWP apps]
Minimum supported server	Windows Server 2012 [desktop apps \| UWP apps]
Target Platform	Windows
Header	timezoneapi.h (include Windows.h)
Library	advapi32.lib
DLL	advapi32.dll