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.Dd $Mdocdate: January 29 2015 $
.Dt TIME 3
.Os
.Sh NAME
.Nm time
.Nd get time of day
.Sh SYNOPSIS
.In time.h
.Ft time_t
.Fn time "time_t *tloc"
.Sh DESCRIPTION
The
.Fn time
function returns the value of time in seconds since 0 hours, 0 minutes,
0 seconds, January 1, 1970, Coordinated Universal Time (UTC).
.Pp
A copy of the time value may be saved to the area indicated by the
pointer
.Fa tloc .
If
.Fa tloc
is a null pointer, no value is stored.
.Sh RETURN VALUES
Upon successful completion,
.Fn time
returns the value of time.
Otherwise a value of
.Po Fa time_t Pc Ns -1
is returned and the global variable
.Va errno
is set to indicate the error.
.Sh ERRORS
The following error codes may be set in
.Va errno :
.Bl -tag -width Er
.It Bq Er EFAULT
An argument address referenced invalid memory.
.El
.Sh SEE ALSO
.Xr clock_gettime 2 ,
.Xr gettimeofday 2 ,
.Xr ctime 3
.Sh HISTORY
A
.Fn time
system call first appeared in
.At v1
and used to return time in sixtieths of a second in 32 bits,
which was to guarantee a crisis every 2.26 years.
Since
.At v6 ,
.Fn time
scale was changed to seconds, extending the pre-crisis stagnation
period up to a total of 68 years.