for the formal man page.- clock add timeVal ?count unit...? ?-option value?
- clock clicks ?-option?
- clock format timeVal ?-option value...?
- clock microseconds
- clock milliseconds
- clock scan inputString ?-option value...?
- clock seconds
Beyond that, try the %Q format:
AM The clock command manipulates an integer number that starts at zero at the "epoch" (1 january 1970, IIRC, on UNIX and many other systems). This limits the valid range of dates a bit.Some experimentation however shows that the range 1 january 1902 to "31 december 2038'' is acceptable on UNIX and Windows. This may not include all dates of birth of now-living people, but it goes a long way. For the Mac this may be a slightly different range (1904-2039).LV Actually, the range depends on the OS and the version of Tcl. For instance, using Tcl 8.5 on SPARC Solaris, I see:
LV To use clock to provide today's date and time formatted, type
You can format relative time in seconds to h:m:s format. Just make sure you pretend to be in Greenwich( -gmt 1), otherwise your local timezone may be added. (RS)
rmax: Is there any chance to tell [clock format] to use another timezone than local or GMT?
Traditional degrees: clock format can be put to un-timely uses. As degrees especially in geography are also subdivided in minutes and seconds, how's this one-liner for formatting decimal degrees:
Want to format the modification time of a specific file? Try
To get back, from clock, yesterday's date, use
See "timezone" for a list of recognized timezones.
In the year 2002, the first week reported by %w is 00. To get more natural numbers starting from 1 (and without leading zero), use
NEM -- From a question in comp.lang.tcl and a session on the chat, here is a proc for getting the start and end days of a week given a week number (0-51):
Here is a little procedure that will let you do timestamping accurate to the millisecond. It requires Tcl 8.4 or greater; while 8.3 supports [clock clicks -milliseconds], the 'clicks' and the 'seconds' are not properly synchronized on all platforms. The procedure was originally sent by Kevin Kenny on comp.lang.tcl. I have modified it a bit so that it can give back the second and millisecond information separately to the caller. EF
Relative time access by hours, minutes, seconds: If you work with relative times in seconds, you can extract its components with [clock scan] and [clock format], but you can also do it with direct arithmetics (RS):
KBK (2004-11-29) wishes to open a discussion on the subject of Parsing ISO8601 dates and times
DKF (2005-05-30): Working out someone's age can be tricky. Luckily, the clock command (with some helping expr trickery) can provide a lot of support for this.
KBK: "http://www.cl.cam.ac.uk/~mgk25/uts.txt is Tcl's model of time ..."
MG See also Bag of number/time spellers
Draft of text which might be easier for beginners to readClock is a tool for, you guessed it, looking at a clock. Your computer has a little clock inside of it that ticks off all of the seconds of the day and night. Computers being such math whizzes, like to think about the time of day in seconds. In fact, with microsoft windows machines, that number of seconds they keep counting, is how many have passed since midnight of the turning of the year between 1969 and 1970. The span of years over which computers count the seconds has been named in dramatic language: "the epoch."In fact, checking my computer's time, right now, I see that it says that there have been one billion, one hundred fifty million seconds which have passed in this epoch, so far. 1,157,998,843 to be exact.And if you're curious, computers do take into account the extra seconds for leap day, every four years.Check what time it is on your computer:
LV I'm confused by this code:
Here's how to get the first day of the current month.
Kevin tells [1] in a Reddit thread a little about the wonderfulness [2] that clock became with 8.5.
AMG: The Tcl 8.4 synopsis for the [clock] command: "Obtain and manipulate time" [3]. Godlike.
% clock format [clock scan now] -format %Q Stardate 56657.7See also Star Trek, A little A/D clock
AM The clock command manipulates an integer number that starts at zero at the "epoch" (1 january 1970, IIRC, on UNIX and many other systems). This limits the valid range of dates a bit.Some experimentation however shows that the range 1 january 1902 to "31 december 2038'' is acceptable on UNIX and Windows. This may not include all dates of birth of now-living people, but it goes a long way. For the Mac this may be a slightly different range (1904-2039).LV Actually, the range depends on the OS and the version of Tcl. For instance, using Tcl 8.5 on SPARC Solaris, I see:
$ tclsh8.5 % clock format [clock scan "January 1, 2040"] Sun Jan 01 00:00:00 EST 2040whereas on the same machine I also see:
$ tclsh8.4 % clock format [clock scan "January 1, 2040"] unable to convert date-time string "January 1, 2040" % clock format [clock scan "Dec 31, 2038"] unable to convert date-time string "Dec 31, 2038" %
LV To use clock to provide today's date and time formatted, type
clock format [clock scan now]
From news:comp.lang.tcl
You can format relative time in seconds to h:m:s format. Just make sure you pretend to be in Greenwich( -gmt 1), otherwise your local timezone may be added. (RS)
clock format 711 -format %H:%M:%S -gmt 1 01:11:51See Formatting durations also.
rmax: Is there any chance to tell [clock format] to use another timezone than local or GMT?
patthoyts: % set env(TZ) GMT ; clock format [clock seconds] Wed Jan 30 16:07:47 GMT 2002 % set env(TZ) GMT+2 ; clock format [clock seconds] Wed Jan 30 14:07:52 GMT 2002"Use" means several different things; here's a different example of clock's intelligence about timezones:
clock format [clock seconds] -format "%X %x" -locale fi_FI -timezone EETLV When I try this, on either Tcl 8.4 or 8.5, I get an error:
$ tclsh8.4 % clock format [clock seconds] -format "%X %x" -locale fi_FI -timezone EET wrong # args: should be "clock format clockval ?-format string? ?-gmt boolean?" % srv22 (139) $ tclsh8.5 % clock format [clock seconds] -format "%X %x" -locale fi_FI -timezone EET time zone EET not foundLV Okay, the problem is this -- the -timezone value needs to start with a colon.
$ tclsh8.5 % clock format [clock seconds] -format "%X %x" -locale fi_FI -timezone :EET 15:52:01 9.02.2007
Traditional degrees: clock format can be put to un-timely uses. As degrees especially in geography are also subdivided in minutes and seconds, how's this one-liner for formatting decimal degrees:
proc dec2deg x {concat [expr int($x)]\u00B0 [clock format [expr round($x*3600)] -format "%M' %S\"" -gmt 1]}The additional -gmt 1 switch is needed if you happen to live in a non-integer timezone. (RS)Want to format the modification time of a specific file? Try
clock format [file mtime "/path/to/my/file"]where you replace /path/to/my/file with the path you want. Or replace it with a variable containing the path.
To get back, from clock, yesterday's date, use
clock format [clock scan yesterday]
See "timezone" for a list of recognized timezones.
In the year 2002, the first week reported by %w is 00. To get more natural numbers starting from 1 (and without leading zero), use
expr [scan [clock format [clock sec] -format %W] %d]+1 ;#RSThis was not the case in the years {1973 1979 1990 1996 2001 2007 2018 2024 2029 2035}, a distance sequence of 6-5-6-11.., where the first week was 01... Hence this cleanup routine, where Jan 1 is always in week 1:
proc week {date} {
set week [scan [clock format $date -format %W] %d]
set year [clock format $date -format %Y]
if {[lsearch {
1973 1979 1990 1996 2001 2007 2018 2024 2029 2035
} $year] < 0} {
incr week
}
set week
} ;# RS - but better just use %V:Kevin Kenny wrote on this question in comp.lang.tcl on 2001-01-07, so in week 01 ;-): The format group, %V, yields the ISO8601 fiscal week number. It's inexplicably missing from the documentation in 8.3; this has been fixed in 8.4.By the way, lots of companies in the US (my employer is NOT one) use a fiscal week numbering system where week 1 begins on the first Sunday of the year rather than on the Monday before the first Thursday.NEM -- From a question in comp.lang.tcl and a session on the chat, here is a proc for getting the start and end days of a week given a week number (0-51):
proc dates {date} {
set date [clock scan "$date weeks" -base [clock scan "01/01/2002"]]
set st [clock scan "sunday" -base [expr {$date - 436800}]]
set end [clock scan "saturday" -base $date]
return [list [clock format $st] [clock format $end]]
}Thus,dates 48gives
{Sun Dec 01 00:00:00 GMT 2002} {Sat Dec 07 00:00:00 GMT 2002}NEM -- After some heckling on comp.lang.tcl for not allowing you to specify a year, or what day the week starts on, here is an improvement: proc dates {date {year now} {day "Sunday"}} {
set days [list sun mon tue wed thu fri sat]
set day [string tolower [string range $day 0 2]]
if {[string equal $year now]} {
set year [clock format [clock scan now] -format %Y]
}
set date [clock scan "$date weeks" -base [clock scan "01/01/$year"]]
set st [clock scan $day -base [expr {$date - 436800}]]
set endday [lsearch $days $day]
set endday [expr {($endday - 1) % 7}]
set endday [lindex $days $endday]
set end [clock scan $endday -base $date]
return [list $st $end]
}It does all the necessary magic. It also returns the numbers rather than pre-formatting them, as this is more flexible. One improvement would be to allow specifying the end day of the week as well (for working weeks, etc). You could do this with an extra parameter, and only calculating the endday if it was not set.Here is a little procedure that will let you do timestamping accurate to the millisecond. It requires Tcl 8.4 or greater; while 8.3 supports [clock clicks -milliseconds], the 'clicks' and the 'seconds' are not properly synchronized on all platforms. The procedure was originally sent by Kevin Kenny on comp.lang.tcl. I have modified it a bit so that it can give back the second and millisecond information separately to the caller. EF
package require Tcl 8.4
proc timestamp { { tv_sec_p "" } { tv_msec_p "" } } {
if { $tv_sec_p != "" } {
upvar $tv_sec_p secs
}
if { $tv_msec_p != "" } {
upvar $tv_msec_p fract
}
set secs [clock seconds]
set ms [clock clicks -milliseconds]
set base [expr { $secs * 1000 }]
set fract [expr { $ms - $base }]
if { $fract >= 1000 } {
set diff [expr { $fract / 1000 }]
incr secs $diff
incr fract [expr { -1000 * $diff }]
}
return $secs.[format %03d $fract]
}MH (2005-10-04) Never mind.. Should have tested it first. Works as advertised :-)EF (2007-09-26) Procedure above slightly modified to fix a tiny bug reported by Tim Tomkinson. Thanks.JYL I needed a calculator for the difference between two timestamps as produced by the above, so here is the code I came up with: proc timestampDiff {ts1 ts2} {
foreach {s1 f1} [split $ts1 '.'] {}
foreach {s2 f2} [split $ts2 '.'] {}
set f1 [string trimleft $f1 '0']
set f2 [string trimleft $f2 '0']
# Unpredictable results if the timestamp s2.f2
# precedes s1.f1!!!
set fd [expr {$f2 - $f1}]
if {$fd < 0} {
set fd [expr {1000 + $fd}]
incr s2 -1
}
set sd [expr {$s2 - $s1}]
return $sd.[format %03d $fd]
}Relative time access by hours, minutes, seconds: If you work with relative times in seconds, you can extract its components with [clock scan] and [clock format], but you can also do it with direct arithmetics (RS):
proc time'h time {expr {($time%86400)/3600}}
proc time'm time {expr {($time%3600)/60}}
proc time's time {expr {$time%60}}KBK (2004-11-29) wishes to open a discussion on the subject of Parsing ISO8601 dates and times
DKF (2005-05-30): Working out someone's age can be tricky. Luckily, the clock command (with some helping expr trickery) can provide a lot of support for this.
# Date-of-birth (in seconds relative to epoch) in $dob
foreach {Ynow CMPnow} [clock format [clock seconds] -format "%Y 1%m%d"] {}
foreach {Ydob CMPdob} [clock format $dob -format "%Y 1%m%d"] {}
set ageInYears [expr { $Ynow-$Ydob-($CMPnow<$CMPdob) }]KBK: "http://www.cl.cam.ac.uk/~mgk25/uts.txt
is Tcl's model of time ..."MG See also Bag of number/time spellers
Draft of text which might be easier for beginners to readClock is a tool for, you guessed it, looking at a clock. Your computer has a little clock inside of it that ticks off all of the seconds of the day and night. Computers being such math whizzes, like to think about the time of day in seconds. In fact, with microsoft windows machines, that number of seconds they keep counting, is how many have passed since midnight of the turning of the year between 1969 and 1970. The span of years over which computers count the seconds has been named in dramatic language: "the epoch."In fact, checking my computer's time, right now, I see that it says that there have been one billion, one hundred fifty million seconds which have passed in this epoch, so far. 1,157,998,843 to be exact.And if you're curious, computers do take into account the extra seconds for leap day, every four years.Check what time it is on your computer:
clock secondsBecause humans' minds are quite boggled by such a large number, TCL makes it easy to read the time in a way we are more accustomed to.
set unweildytime [clock seconds] clock format $unweildytime -format %x clock format $unweildytime -format %rDid you see what happened there? First we had to get the gargantuan number of seconds... and then we had to give that number to our clock tool again. Unfortunately, we have to use the word format twice on the same line; that makes it a bit harder to read. And what is that percentage thingy? That is how we tell TCL the pattern we wish to see things in.If you want ALL the details, here are the patterns which you can request:
- %a -- the abbreviated english language weekday name (Mon, Tue, etc.).
- %A -- the full english weekday name (Monday, Tuesday, etc.).
- %b -- an abbreviated month name (Jan, Feb, etc.).
- %B -- the full month name.
- %C -- the first two digits of the four-digit year (19 or 20).
- %d -- day of month (01 - 31).
- %e -- day of month (1 - 31) with no leading zeros.
- %h -- the abbreviated month name.
- %H -- the hour in 24-hour format (00 - 23).
- %I -- the hour in 12-hour format (01 - 12).
- %j -- the numbered day of the year (001 - 366).
- %k -- the hour in 24-hour format, without leading zeros (0 - 23).
- %l -- the hour in 12-hour format, without leading zeros (1 - 12).
- %m -- The month number (01 - 12).
- %M -- minute (00 - 59).
- %p -- AM/PM indicator.
- %S -- seconds (00 - 59).
- %u -- The day of the week as a number (Monday = 1, Sunday = 7).
- %U -- the numbered week of the current year (00 - 52). Here, Sunday is considered the first day of the week.)
- %w -- weekday as a number (Sunday = 0, Saturday = 6).
- %W -- the week of the year (00 - 52), Monday is the first day of the week.
- %y -- this year without the century noted (00 - 99).
- %Y -- the complete year (e.g. 1990)
- %Z -- Your timezone name ;-)
- %D -- Date as %m/%d/%y.
- %T -- Time as %H:%M:%S.
- %R -- Time as %H:%M.
- %c -- Date and time as your computer normally says them to you. On Unix/macintosh the format for date and time is the default "C" locale: "%a %b %d %H:%M:%S %Y". On microsoft windows, this pattern is specified in the Regional Options control panel settings.
- %x -- Just the date as your computer is accustomed to writing it. Unix/Macintosh form is: "%m/%d/%y".
- %X -- The twenty four hour clock. The Unix/Macintosh form is "%H:%M:%S".
- %r -- The am/pm clock. For Unix/Macintosh, this is "%I:%M:%S %p".
- %t -- Insert a tab.
- %n -- Insert a newline.
- %% -- type the percentage sign, itself
- %g -- The ISO8601 year number corresponding to the ISO8601 week (%V), expressed as a two-digit year-of-the-century, with leading zero if necessary.
- %G -- The ISO8601 year number corresponding to the ISO8601 week (%V), expressed as a four-digit number.
- %Q -- For testing only.
- %V -- Week of year according to ISO-8601 rules. Week 1 of a given year is the week containing 4 January.
- %s -- Count of seconds since the beginning of the epoch, expressed as a decimal integer (yes, this is redundant!)
proc ddate {dt} {
clock format [clock scan $dt]
}
% ddate "2007-1-12 11:00am"
Fri Jan 12 11:00:00 EST 2007
% ddate {1 january 1900}
Mon Jan 01 00:00:00 EST 1900
% ddate 1/1/200
Tue Jan 01 00:00:00 EST 0200
% ddate 1/1/100
Wed Jan 01 00:00:00 EST 0100
% ddate 1/1/99
Fri Jan 01 00:00:00 EST 1999LV I'm confused by this code:
% set n [clock scan "12-1-2007 11:00am"] 1498748400 % puts [clock format $n] Thu Jun 29 11:00:00 EDT 2017Why 2017? There doesn't appear, to me, to be anything in the first string that would be misinterpreted as 2017. I could understand if it were 2012, or even 2001... it would make me sad, but at least I could see how that was reached.schlenk Simple: The year 12 of this century, add one month and 2007 days and you get a date in 2017.slebetman: I just get:
unable to convert date-time string "12-1-2007 11:00am"LV So why is a date in the format listed in the documentation as a valid month, day, year format being treated as some sort of calculation instead?LV Ah -- because the date was input wrong! The format accepted is yyyy-mm-dd:
% clock format [clock scan "2007-1-12 11:00am"] Fri Jan 12 11:00:00 EST 2007
Here's how to get the first day of the current month.
clock format [clock scan 1 -format %d]Here's how to get the last day of the current month.
clock format [clock scan 0 -format %d -base [clock add [clock seconds] 1 month]]
Kevin tells [1] in a Reddit thread a little about the wonderfulness [2] that clock became with 8.5.
AMG: The Tcl 8.4 synopsis for the [clock] command: "Obtain and manipulate time" [3]. Godlike.
See also edit
- A base-5 clock
- A little countdown clock
- An analog clock in Tk
- an analogue countdown clock-face
- An arc clock
- Binary clock
- QLOCKTWO in Tcl
- clock and daylight saving time corrections
- Clock and Timing Granularity
- clock forward compatibility
- clock clicks
- clock milliseconds
- clock seconds
- clock format
- clock.tcl
- curses digital clock
- Date and Time Issues
- Localized clock
- Reworking the clock command
- Digging into the internals of Tcl's clock
- tkclock
- clock weekday conversion toy
- clock differences between 8.4 and 8.5
