How do I get milliseconds since midnight UTC in C?

Question

The time function in time.h gives milliseconds since the epoch.

Answer 1

You use gettimeofday(2) which is defined in POSIX.1 and BSD.

It returns seconds and microseconds as defined in struct timeval from sys/time.h.

Answer 2

You will find C code examples for getting time and converting it to various formats here.

Answer 3

This is a simple way:

time_t seconds_since_midnight = time(NULL) % 86400;

To get approximate milliseconds since midnight, multiply seconds_since_midnight by 1000.

If you need more resolution (consider whether you really do), you will have to use another function such as gettimeofday().

Answer 4

Take a look at gmtime() Converts directly to Coordinated Universal Time (UTC)...