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@(#)time.3 8.1 (Berkeley) 6/4/93
.Dd April 29, 2024 .Dt TIME 3 .Os .Sh NAME .Nm time .Nd get time of day .Sh LIBRARY .Lb libc .Sh SYNOPSIS n 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.
p If .Fa tloc is not a null pointer, a copy of the time value is saved in .Fa *tloc .
p Upon successful completion, .Fn time returns the value of time. Otherwise a value of
o
o Fa time_t Pc Ns -1
c is returned and the global variable .Va errno is set to indicate the error. .Sh ERRORS No errors are defined. .Sh SEE ALSO .Xr gettimeofday 2 , .Xr ctime 3 .Sh STANDARDS The .Fn time function conforms to .St -p1003.1-90 . .Sh HISTORY A .Fn time function appeared in .At v2 . It returned a 32-bit value measuring sixtieths of a second, leading to rollover every 2.26 years. In .At v6 , the precision of .Fn time was changed to seconds, allowing 135.6 years between rollovers.
p In .Nx 6.0 the .Vt 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 .Vt time_t is the same as .Vt long will fail on 32-bit machines in 2038.
Indexes created Sun Nov 02 07:10:05 GMT 2025