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+.\" Copyright (c) 1980, 1991, 1993
+.\" The Regents of the University of California. All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\" notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\" notice, this list of conditions and the following disclaimer in the
+.\" documentation and/or other materials provided with the distribution.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\" may be used to endorse or promote products derived from this software
+.\" without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" @(#)gettimeofday.2 8.2 (Berkeley) 5/26/95
+.\" $FreeBSD$
+.\"
+.Dd May 26, 1995
+.Dt GETTIMEOFDAY 2
+.Os
+.Sh NAME
+.Nm gettimeofday ,
+.Nm settimeofday
+.Nd get/set date and time
+.Sh LIBRARY
+.Lb libc
+.Sh SYNOPSIS
+.In sys/time.h
+.Ft int
+.Fn gettimeofday "struct timeval *tp" "struct timezone *tzp"
+.Ft int
+.Fn settimeofday "const struct timeval *tp" "const struct timezone *tzp"
+.Sh DESCRIPTION
+.Bf -symbolic
+Note: timezone is no longer used; this information is kept outside
+the kernel.
+.Ef
+.Pp
+The system's notion of the current Greenwich time and the current time
+zone is obtained with the
+.Fn gettimeofday
+system call, and set with the
+.Fn settimeofday
+system call.
+The time is expressed in seconds and microseconds
+since midnight (0 hour), January 1, 1970.
+The resolution of the system
+clock is hardware dependent, and the time may be updated continuously or
+in
+.Dq ticks .
+If
+.Fa tp
+or
+.Fa tzp
+is NULL, the associated time
+information will not be returned or set.
+.Pp
+The structures pointed to by
+.Fa tp
+and
+.Fa tzp
+are defined in
+.In sys/time.h
+as:
+.Bd -literal
+struct timeval {
+ time_t tv_sec; /* seconds */
+ suseconds_t tv_usec; /* and microseconds */
+};
+
+struct timezone {
+ int tz_minuteswest; /* minutes west of Greenwich */
+ int tz_dsttime; /* type of dst correction */
+};
+.Ed
+.Pp
+The
+.Vt timezone
+structure indicates the local time zone
+(measured in minutes of time westward from Greenwich),
+and a flag that, if nonzero, indicates that
+Daylight Saving time applies locally during
+the appropriate part of the year.
+.Pp
+Only the super-user may set the time of day or time zone.
+If the system is running at securelevel >= 2 (see
+.Xr init 8 ) ,
+the time may only be advanced or retarded by a maximum of one second.
+This limitation is imposed to prevent a malicious super-user
+from setting arbitrary time stamps on files.
+The system time can be adjusted backwards without restriction using the
+.Xr adjtime 2
+system call even when the system is secure.
+.Sh RETURN VALUES
+.Rv -std
+.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.
+.It Bq Er EPERM
+A user other than the super-user attempted to set the time.
+.El
+.Sh SEE ALSO
+.Xr date 1 ,
+.Xr adjtime 2 ,
+.Xr clock_gettime 2 ,
+.Xr ctime 3 ,
+.Xr timeradd 3 ,
+.Xr clocks 7 ,
+.Xr timed 8
+.Sh HISTORY
+The
+.Fn gettimeofday
+system call appeared in
+.Bx 4.2 .
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