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ActiveTcl User Guide
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- NAME
- clock - Obtain and manipulate time
- SYNOPSIS
- clock option ?arg arg ...?
- DESCRIPTION
- .VS 8.3
- clock format
clockValue ?-format string? ?-gmt
boolean?
- %%
- %a
- %A
- %b
- %B
- %c
- %C
- %d
- %D
- %e
- %h
- %H
- %I
- %j
- %k
- %l
- %m
- %M
- %n
- %p
- %r
- %R
- %s
- %S
- %t
- %T
- %u
- %U
- %V
- %w
- %W
- %x
- %X
- %y
- %Y
- %Z
- clock scan
dateString ?-base clockVal? ?-gmt
boolean?
- time
- date
- ISO 8601
point-in-time
- relative
time
- clock
seconds
- SEE ALSO
- KEYWORDS
clock - Obtain and manipulate time
clock option ?arg arg ...?
This command performs one of several operations that may obtain
or manipulate strings or values that represent some notion of time.
The option argument determines what action is carried out by
the command. The legal options (which may be abbreviated)
are:
- .VS 8.3
- clock clicks ?-milliseconds? Return a
high-resolution time value as a system-dependent integer value. The
unit of the value is system-dependent but should be the highest
resolution clock available on the system such as a CPU cycle
counter. If -milliseconds is specified, then the value is
guaranteed to be of millisecond granularity. This value should only
be used for the relative measurement of elapsed time.
- clock format clockValue
?-format string? ?-gmt
boolean?
- Converts an integer time value, typically returned by clock
seconds, clock scan, or the atime, mtime,
or ctime options of the file command, to human-readable form.
If the -format argument is present the next argument is a
string that describes how the date and time are to be formatted.
Field descriptors consist of a % followed by a field
descriptor character. All other characters are copied into the
result. Valid field descriptors are:
- %%
- Insert a %.
- %a
- Abbreviated weekday name (Mon, Tue, etc.).
- %A
- Full weekday name (Monday, Tuesday, etc.).
- %b
- Abbreviated month name (Jan, Feb, etc.).
- %B
- Full month name.
- %c
- Locale specific date and time. The format for date and time in
the default "C" locale on Unix/Mac is "%a %b %d %H:%M:%S %Y". On
Windows, this value is the locale specific long date and time, as
specified in the Regional Options control panel settings.
- %C
- First two digits of the four-digit year (19 or 20).
- %d
- Day of month (01 - 31).
- %D
- Date as %m/%d/%y.
- %e
- Day of month (1 - 31), no leading zeros.
- %h
- Abbreviated month name.
- %H
- Hour in 24-hour format (00 - 23).
- %I
- Hour in 12-hour format (01 - 12).
- %j
- Day of year (001 - 366).
- %k
- Hour in 24-hour format, without leading zeros (0 - 23).
- %l
- Hour in 12-hour format, without leading zeros (1 - 12).
- %m
- Month number (01 - 12).
- %M
- Minute (00 - 59).
- %n
- Insert a newline.
- %p
- AM/PM indicator.
- %r
- Time in a locale-specific "meridian" format. The "meridian"
format in the default "C" locale is "%I:%M:%S %p".
- %R
- Time as %H:%M.
- %s
- Count of seconds since the epoch, expressed as a decimal
integer.
- %S
- Seconds (00 - 59).
- %t
- Insert a tab.
- %T
- Time as %H:%M:%S.
- %u
- Weekday number (Monday = 1, Sunday = 7).
- %U
- Week of year (00 - 52), Sunday is the first day of the
week.
- %V
- Week of year according to ISO-8601 rules. Week 1 of a given
year is the week containing 4 January.
- %w
- Weekday number (Sunday = 0, Saturday = 6).
- %W
- Week of year (00 - 52), Monday is the first day of the
week.
- %x
- Locale specific date format. The format for a date in the
default "C" locale for Unix/Mac is "%m/%d/%y". On Windows, this
value is the locale specific short date format, as specified in the
Regional Options control panel settings.
- %X
- Locale specific 24-hour time format. The format for a 24-hour
time in the default "C" locale for Unix/Mac is "%H:%M:%S". On
Windows, this value is the locale specific time format, as
specified in the Regional Options control panel settings.
- %y
- Year without century (00 - 99).
- %Y
- Year with century (e.g. 1990)
- %Z
- Time zone name.
If the -format argument is not specified, the format
string "%a %b %d %H:%M:%S %Z %Y" is used. If the -gmt
argument is present the next argument must be a boolean which if
true specifies that the time will be formatted as Greenwich Mean
Time. If false then the local timezone will be used as defined by
the operating environment.
- clock scan dateString ?-base
clockVal? ?-gmt boolean?
- Convert dateString to an integer clock value (see
clock seconds). This command can parse and convert virtually
any standard date and/or time string, which can include standard
time zone mnemonics. If only a time is specified, the current date
is assumed. If the string does not contain a time zone mnemonic,
the local time zone is assumed, unless the -gmt argument is
true, in which case the clock value is calculated assuming that the
specified time is relative to Greenwich Mean Time. -gmt, if
specified, affects only the computed time value; it does not impact
the interpretation of -base.
If the -base flag is specified, the next argument should
contain an integer clock value. Only the date in this value is
used, not the time. This is useful for determining the time on a
specific day or doing other date-relative conversions.
The dateString consists of zero or more specifications of
the following form:
- time
- A time of day, which is of the form:
hh?:mm?:ss?? ?meridian? ?zone?
or hhmm ?meridian? ?zone?. If no meridian is
specified, hh is interpreted on a 24-hour clock.
- date
- A specific month and day with optional year. The acceptable
formats are mm/dd?/yy?, monthname dd ?,
yy?, dd monthname ?yy?, day, dd monthname
yy, ?CC?yymmdd, ?CC?yy-mm-dd,
dd-monthname-?CC?yy. The default year is the current year.
If the year is less than 100, we treat the years 00-68 as 2000-2068
and the years 69-99 as 1969-1999. Not all platforms can represent
the years 38-70, so an error may result if these years are
used.
- ISO 8601 point-in-time
- An ISO 8601 point-in-time specification, such as
CCyymmddThhmmss, where T is the literal T, CCyymmdd
hhmmss, or CCyymmddThh:mm:ss.
- relative time
- A specification relative to the current time. The format is
number unit acceptable units are year,
fortnight, month, week, day,
hour, minute (or min), and second (or
sec). The unit can be specified as a singular or plural, as
in 3 weeks. These modifiers may also be specified:
tomorrow, yesterday, today, now,
last, this, next, ago.
- The actual date is calculated according to the following steps.
First, any absolute date and/or time is processed and converted.
Using that time as the base, day-of-week specifications are added.
Next, relative specifications are used. If a date or day is
specified, and no absolute or relative time is given, midnight is
used. Finally, a correction is applied so that the correct hour of
the day is produced after allowing for daylight savings time
differences and the correct date is given when going from the end
of a long month to a short month.
Daylight savings time correction is applied only when the
relative time is specified in units of days or more, ie, days,
weeks, fortnights, months or years. This means that when crossing
the daylight savings time boundary, different results will be given
for clock scan "1 day" and clock scan "24 hours":
% clock scan "1 day" -base [clock scan 1999-10-31]
941443200
% clock scan "24 hours" -base [clock scan 1999-10-31]
941439600
- clock seconds
- Return the current date and time as a system-dependent integer
value. The unit of the value is seconds, allowing it to be used for
relative time calculations. The value is usually defined as total
elapsed time from an ``epoch''. You shouldn't assume the value of
the epoch.
date, time
clock, date, time
Copyright © 1992-1995 Karl Lehenbauer and Mark Diekhans.
Copyright © 1995-1997 Sun Microsystems, Inc.
Copyright © 1998-1999 Scriptics Corporation
Copyright © 2002 ActiveState Corporation
Copyright © 1995-1997 Roger E. Critchlow Jr.