Tcl Source Code

exactly 86400 seconds.  Tcl responds to leap seconds by speeding or
slowing its clock by a tiny fraction for some minutes until it is
back in sync with UTC; its data model does not represent minutes that
have 59 or 61 seconds.
.TP
\fIunit\fR
One of the words, \fBseconds\fR, \fBminutes\fR, \fBhours\fR,
\fBdays\fR, \fBweeks\fR, \fBmonths\fR, or \fByears\fR, or
any unique prefix of such a word. Used in conjunction with \fIcount\fR
to identify an interval of time, for example, \fI3 seconds\fR or
\fBdays\fR, \fBweekdays\fR, \fBweeks\fR, \fBmonths\fR, or \fByears\fR.
Used in conjunction with \fIcount\fR to identify an interval of time,
for example, \fI3 seconds\fR or \fI1 year\fR.
\fI1 year\fR.
.SS "OPTIONS"
.TP
\fB\-base\fR time
Specifies that any relative times present in a \fBclock scan\fR command
are to be given relative to \fItime\fR.  \fItime\fR must be expressed as
a count of nominal seconds from the epoch time of 1 January 1970, 00:00 UTC.
.TP

.PP
The \fBclock add\fR command performs clock arithmetic on a value
(expressed as nominal seconds from the epoch time of 1 January 1970, 00:00 UTC)
given as its first argument.  The remaining arguments (other than the
possible \fB\-timezone\fR, \fB\-locale\fR and \fB\-gmt\fR options)
are integers and keywords in alternation, where the keywords are chosen
from \fBseconds\fR, \fBminutes\fR, \fBhours\fR,
\fBdays\fR, \fBweeks\fR, \fBmonths\fR, or \fByears\fR, or
\fBdays\fR, \fBweekdays\fR, \fBweeks\fR, \fBmonths\fR, or \fByears\fR.
any unique prefix of such a word.
.PP
Addition of seconds, minutes and hours is fairly straightforward;
the given time increment (times sixty for minutes, or 3600 for hours)
is simply added to the \fItimeVal\fR given
to the \fBclock add\fR command.  The result is interpreted as
a nominal number of seconds from the Epoch.
.PP

.CE
.PP
Adding and subtracting days and weeks is accomplished by converting
the given time to a calendar day and time of day in the appropriate
time zone and locale.  The requisite number of days (weeks are converted
to days by multiplying by seven) is added to the calendar day, and
the date and time are then converted back to a count of seconds from
the epoch time.
the epoch time.  The \fBweekdays\fR keyword is similar to \fBdays\fR,
with the only difference that weekends - Saturdays and Sundays - are skipped.
.PP
Adding and subtracting a given number of days across the point that
the time changes at the start or end of summer time (Daylight Saving Time)
results in the \fIsame local time\fR on the day in question.  For
instance, the following code sets the value of \fBx\fR to \fB05:00:00\fR.
.PP
.CS

 */

#if (FLT_RADIX == 2) && (DBL_MANT_DIG == 53) && (DBL_MAX_EXP == 1024)
#define IEEE_FLOATING_POINT
#endif

/*
 * A mask (should be 2**n-1) that is used to work out when the bytecode engine
 * should call Tcl_AsyncReady() to see whether there is a signal that needs
 * handling.
 * A counter that is used to work out when the bytecode engine should call
 * Tcl_AsyncReady() to see whether there is a signal that needs handling, and
 * other expensive periodic operations.
 */

#ifndef ASYNC_CHECK_COUNT_MASK
#   define ASYNC_CHECK_COUNT_MASK	63
#endif /* !ASYNC_CHECK_COUNT_MASK */
#ifndef ASYNC_CHECK_COUNT
#   define ASYNC_CHECK_COUNT	64
#endif /* !ASYNC_CHECK_COUNT */

/*
 * Boolean flag indicating whether the Tcl bytecode interpreter has been
 * initialized.
 */

static int execInitialized = 0;

     */

    /*
     * Constants: variables that do not change during the execution, used
     * sporadically: no special need for speed.
     */

    int instructionCount = ASYNC_CHECK_COUNT;
    int instructionCount = 0;	/* Counter that is used to work out when to
				/* Counter that is used to work out when to
				 * call Tcl_AsyncReady() */
    const char *curInstName;
#ifdef TCL_COMPILE_DEBUG
    int traceInstructions;	/* Whether we are doing instruction-level
				 * tracing or not. */
#endif

	break;
    }
  cleanup0:

    /*
     * Check for asynchronous handlers [Bug 746722]; we do the check every
     * ASYNC_CHECK_COUNT_MASK instruction, of the form (2**n-1).
     * ASYNC_CHECK_COUNT instructions.
     */

    if (!(--instructionCount)) {
    if ((instructionCount++ & ASYNC_CHECK_COUNT_MASK) == 0) {
	instructionCount = ASYNC_CHECK_COUNT;
	DECACHE_STACK_INFO();
	if (TclAsyncReady(iPtr)) {
	    result = Tcl_AsyncInvoke(interp, result);
	    if (result == TCL_ERROR) {
		CACHE_STACK_INFO();
		goto gotError;
	    }

	return -code error \
	    -errorcode [list CLOCK wrongNumArgs] \
	    "wrong \# args: should be\
             \"$cmdName clockval ?number units?...\
             ?-gmt boolean? ?-locale LOCALE? ?-timezone ZONE?\""
    }
    if { [catch { expr {wide($clockval)} } result] } {
	return -code error $result
	return -code error "expected integer but got \"$clockval\""
    }

    set offsets {}
    set gmt 0
    set locale c
    set timezone [GetSystemTimeZone]

    # Check options for validity

    if { [info exists saw(-gmt)] && [info exists saw(-timezone)] } {
	return -code error \
	    -errorcode [list CLOCK gmtWithTimezone] \
	    "cannot use -gmt and -timezone in same call"
    }
    if { [catch { expr { wide($clockval) } } result] } {
	return -code error "expected integer but got \"$clockval\""
    }
    if { ![string is boolean -strict $gmt] } {
	return -code error "expected boolean value but got \"$gmt\""
    } elseif { $gmt } {
	set timezone :GMT
    }

    EnterLocale $locale

		    set clockval [AddDays [expr { 7 * $quantity }] \
			    $clockval $timezone $changeover]
		}
		days - day {
		    set clockval [AddDays $quantity $clockval $timezone \
			    $changeover]
		}

		weekdays - weekday {
		    set clockval [AddWeekDays $quantity $clockval $timezone \
			    $changeover]
		}

		hours - hour {
		    set clockval [expr { 3600 * $quantity + $clockval }]
		}
		minutes - minute {
		    set clockval [expr { 60 * $quantity + $clockval }]
		}

    }]
    set date [ConvertLocalToUTC $date[set date {}] $TZData($timezone) \
		 $changeover]

    return [dict get $date seconds]

}

#----------------------------------------------------------------------
#
# AddWeekDays --
#
#	Add a given number of week days (skipping Saturdays and Sundays)
#	to a given clock value in a given time zone.
#
# Parameters:
#	days - Number of days to add (may be negative)
#	clockval - Seconds since the epoch before the operation
#	timezone - Time zone in which the operation is to be performed
#	changeover - Julian Day on which the Gregorian calendar was adopted
#		     in the target locale.
#
# Results:
#	Returns the new clock value as a number of seconds since the epoch.
#
# Side effects:
#	None.
#
#----------------------------------------------------------------------

proc ::tcl::clock::AddWeekDays { days clockval timezone changeover } {

    if {$days == 0} {
        return $clockval
    }

    set day [format $clockval -format %u]

    set weeks  [expr {$days / 5}]
    set rdays  [expr {$days % 5}]
    set toAdd  [expr {7 * $weeks + $rdays}]
    set resDay [expr {$day + ($toAdd % 7)}]

    # Adjust if we start from a weekend
    if {$day > 5} {
	set adj [expr {5 - $day}]
	incr toAdd  $adj
	incr resDay $adj
    }

    # Adjust if we end up on a weekend
    if {$resDay > 5} {
	incr toAdd 2
    }

    AddDays $toAdd $clockval $timezone $changeover
}

#----------------------------------------------------------------------
#
# AddDays --
#
#	Add a given number of days to a given clock value in a given time
#	zone.

test clock-29.1800 {time parsing} {
    clock scan {2440588 xi:lix:lix pm} \
        -gmt true -locale en_US_roman \
        -format {%J %Ol:%OM:%OS %P}
} 86399
# END testcases29


# BEGIN testcases30

# Test [clock add]
test clock-30.1 {clock add years} {
    set t [clock scan 2000-01-01 -format %Y-%m-%d -timezone :UTC]
    set f [clock add $t 1 year -timezone :UTC]
    clock format $f -format %Y-%m-%d -timezone :UTC
} {2001-01-01}
test clock-30.2 {clock add years - leap day} {
    set t [clock scan 2000-02-29 -format %Y-%m-%d -timezone :UTC]

    set t [clock scan {2004-10-31 01:00:00 -0400} \
	       -format {%Y-%m-%d %H:%M:%S %z} \
	       -timezone EST05:00EDT04:00,M4.1.0/02:00,M10.5.0/02:00]
    set f1 [clock add $t 3600 seconds -timezone EST05:00EDT04:00,M4.1.0/02:00,M10.5.0/02:00]
    set x1 [clock format $f1 -format {%Y-%m-%d %H:%M:%S %z} \
		-timezone EST05:00EDT04:00,M4.1.0/02:00,M10.5.0/02:00]
} {2004-10-31 01:00:00 -0500}
test clock-30.26 {clock add weekdays} {
    set t [clock scan {2013-11-20}] ;# Wednesday
    set f1 [clock add $t 3 weekdays]
    set x1 [clock format $f1 -format {%Y-%m-%d}]
} {2013-11-25}
test clock-30.27 {clock add weekdays starting on Saturday} {
    set t [clock scan {2013-11-23}] ;# Saturday
    set f1 [clock add $t 1 weekday]
    set x1 [clock format $f1 -format {%Y-%m-%d}]
} {2013-11-25}
test clock-30.28 {clock add weekdays starting on Sunday} {
    set t [clock scan {2013-11-24}] ;# Sunday
    set f1 [clock add $t 1 weekday]
    set x1 [clock format $f1 -format {%Y-%m-%d}]
} {2013-11-25}
test clock-30.29 {clock add 0 weekdays starting on a weekend} {
    set t [clock scan {2016-02-27}] ;# Saturday
    set f1 [clock add $t 0 weekdays]
    set x1 [clock format $f1 -format {%Y-%m-%d}]
} {2016-02-27}
test clock-30.30 {clock add weekdays and back} -body {
    set n [clock seconds]
    # we start on each day of the week
    for {set i 0} {$i < 7} {incr i} {
        set start  [clock add $n $i days]
        set startu [clock format $start -format %u]
        # add 0 - 100 weekdays
        for {set j 0} {$j < 100} {incr j} {
            set forth [clock add $start $j weekdays]
            set back  [clock add $forth -$j weekdays]
            # If $s was a weekday or $j was 0, $b must be the same day.
            # Otherwise, $b must be the immediately preceeding Friday
            set fail 0
            if {$j == 0 || $startu < 6} {
                if {$start != $back} { set fail 1}
            } else {
                set friday [clock add $start -[expr {$startu % 5}] days]
                if {$friday != $back} { set fail 1 }
            }
            if {$fail} {
                set sdate [clock format $start -format {%Y-%m-%d}]
                set bdate [clock format $back  -format {%Y-%m-%d}]
                return "$sdate + $j - $j := $bdate"
            }
        }
    }
    return "OK"
} -result {OK}

# END testcases30


test clock-31.1 {system locale} \
    -constraints win \
    -setup {
	namespace eval ::tcl::clock {
	    namespace import -force ::testClock::registry
	}