void set_dst

void set_dst(int(*)(const time_t *, int32_t *))

Specify the Daylight Saving function.

The Daylight Saving function should examine its parameters to determine whether Daylight Saving is in effect, and return a value appropriate for tm_isdst.

Working examples for the USA and the EU are available..

 #include <util/eu_dst.h>
for the European Union, and
 #include <util/usa_dst.h>
for the United States

If a Daylight Saving function is not specified, the system will ignore Daylight Saving.