TIME(3) | Library Functions Manual | TIME(3)

# NAME

`time` — get time of day

# LIBRARY

Standard C Library (libc, -lc)

# SYNOPSIS

`#include <time.h>`

time_t
`time`(time_t *tloc);

# DESCRIPTION

The `time`() function returns the value of time in seconds since 0 hours, 0 minutes, 0 seconds, January 1, 1970, Coordinated Universal Time.

If tloc is not a null pointer, a copy of the time value is saved in *tloc.

Upon successful completion, `time`() returns the value of time. Otherwise a value of ((time_t)-1) is returned and the global variable errno is set to indicate the error.

# ERRORS

No errors are defined.

# SEE ALSO

gettimeofday(2), ctime(3)

# STANDARDS

The `time`() function conforms to IEEE Std 1003.1-1990 (“POSIX.1”).

# HISTORY

A `time`() function appeared in Version 2 AT&T UNIX. It returned a 32-bit value measuring sixtieths of a second, leading to rollover every 2.26 years. In Version 6 AT&T UNIX, the precision of `time`() was changed to seconds, allowing 135.6 years between rollovers.

In NetBSD 6.0 the time_t type was changed to be 64 bits wide, including on 32-bit machines, making rollover a concern for the far distant future only. Note however that any code making the incorrect assumption that time_t is the same as long will fail on 32-bit machines in 2038.

April 29, 2024 | NetBSD 11.0