mirror of
https://github.com/ruby/ruby.git
synced 2022-11-09 12:17:21 -05:00
[DOC] New page for strftime formats (#6074)
This new page would be linked from method strftime in Time, Date, and DateTime, replacing the text there.
This commit is contained in:
Burdette Lamar
GitHub
parent
3cf0018119
commit
8f5ad74e40
Notes:
git
2022-07-02 05:25:39 +09:00
Merged-By: BurdetteLamar <BurdetteLamar@Yahoo.com>
1 changed files with 463 additions and 0 deletions
463
doc/strftime_formatting.rdoc
Normal file
463
doc/strftime_formatting.rdoc
Normal file
|
|
@ -0,0 +1,463 @@
|
|||
== Formats for Dates and Times
|
||||
|
||||
Several Ruby time-related classes have instance method +strftime+,
|
||||
which returns a formatted string representing all or part of a date or time:
|
||||
|
||||
- Date#strftime.
|
||||
- DateTime#strftime.
|
||||
- Time#strftime.
|
||||
|
||||
Each of these methods takes optional argument +format+,
|
||||
which has zero or more embedded _format_ _specifications_ (see below).
|
||||
|
||||
Each of these methods returns the string resulting from replacing each
|
||||
format specification embedded in +format+ with a string form
|
||||
of one or more parts of the date or time.
|
||||
|
||||
A simple example:
|
||||
|
||||
Time.now.strftime('%H:%M:%S') # => "14:02:07"
|
||||
|
||||
A format specification has the form:
|
||||
|
||||
%[flags][width]conversion
|
||||
|
||||
It consists of:
|
||||
|
||||
- A leading percent character.
|
||||
- Zero or more _flags_ (each is a character).
|
||||
- An optional _width_ _specifier_ (an integer).
|
||||
- A _conversion_ _specifier_ (a character).
|
||||
|
||||
Except for the leading percent character,
|
||||
the only required part is the conversion specifier, so we begin with that.
|
||||
|
||||
=== Conversion Specifiers
|
||||
|
||||
==== \Date (Year, Month, Day)
|
||||
|
||||
- <tt>%Y</tt> - Year including century, zero-padded:
|
||||
|
||||
Time.now.strftime('%Y') # => "2022"
|
||||
Time.new(-1000).strftime('%Y') # => "-1000" # Before common era.
|
||||
Time.new(10000).strftime('%Y') # => "10000" # Far future.
|
||||
Time.new(10).strftime('%Y') # => "0010" # Zero-padded by default.
|
||||
|
||||
- <tt>%y</tt> - Year without century, in range (0.99), zero-padded:
|
||||
|
||||
Time.now.strftime('%y') # => "22"
|
||||
Time.new(1).strftime('%y') # => "01" # Zero-padded by default.
|
||||
|
||||
- <tt>%C</tt> - Century, zero-padded:
|
||||
|
||||
Time.now.strftime('%C') # => "20"
|
||||
Time.new(-1000).strftime('%C') # => "-10" # Before common era.
|
||||
Time.new(10000).strftime('%C') # => "100" # Far future.
|
||||
Time.new(100).strftime('%C') # => "01" # Zero-padded by default.
|
||||
|
||||
- <tt>%m</tt> - Month of the year, in range (1..12), zero-padded:
|
||||
|
||||
Time.new(2022, 1).strftime('%m') # => "01" # Zero-padded by default.
|
||||
Time.new(2022, 12).strftime('%m') # => "12"
|
||||
|
||||
- <tt>%B</tt> - Full month name, capitalized:
|
||||
|
||||
Time.new(2022, 1).strftime('%B') # => "January"
|
||||
Time.new(2022, 12).strftime('%B') # => "December"
|
||||
|
||||
- <tt>%b</tt> - Abbreviated month name, capitalized:
|
||||
|
||||
Time.new(2022, 1).strftime('%b') # => "Jan"
|
||||
Time.new(2022, 12).strftime('%h') # => "Dec"
|
||||
|
||||
- <tt>%h</tt> - Same as <tt>%b</tt>.
|
||||
|
||||
- <tt>%d</tt> - Day of the month, in range (1..31), zero-padded:
|
||||
|
||||
Time.new(2002, 1, 1).strftime('%d') # => "01"
|
||||
Time.new(2002, 1, 31).strftime('%d') # => "31"
|
||||
|
||||
- <tt>%e</tt> - Day of the month, in range (1..31), blank-padded:
|
||||
|
||||
Time.new(2002, 1, 1).strftime('%e') # => " 1"
|
||||
Time.new(2002, 1, 31).strftime('%e') # => "31"
|
||||
|
||||
- <tt>%j</tt> - Day of the year, in range (1..366), zero-padded:
|
||||
|
||||
Time.new(2002, 1, 1).strftime('%j') # => "001"
|
||||
Time.new(2002, 12, 31).strftime('%j') # => "365"
|
||||
|
||||
==== \Time (Hour, Minute, Second, Subsecond)
|
||||
|
||||
- <tt>%H</tt> - Hour of the day, in range (0..23), zero-padded:
|
||||
|
||||
Time.new(2022, 1, 1, 1).strftime('%H') # => "01"
|
||||
Time.new(2022, 1, 1, 13).strftime('%H') # => "13"
|
||||
|
||||
- <tt>%k</tt> - Hour of the day, in range (0..23), blank-padded:
|
||||
|
||||
Time.new(2022, 1, 1, 1).strftime('%k') # => " 1"
|
||||
Time.new(2022, 1, 1, 13).strftime('%k') # => "13"
|
||||
|
||||
- <tt>%I</tt> - Hour of the day, in range (1..12), zero-padded:
|
||||
|
||||
Time.new(2022, 1, 1, 1).strftime('%I') # => "01"
|
||||
Time.new(2022, 1, 1, 13).strftime('%I') # => "01"
|
||||
|
||||
- <tt>%l</tt> - Hour of the day, in range (1..12), blank-padded:
|
||||
|
||||
Time.new(2022, 1, 1, 1).strftime('%l') # => " 1"
|
||||
Time.new(2022, 1, 1, 13).strftime('%l') # => " 1"
|
||||
|
||||
- <tt>%P</tt> - Meridian indicator, lowercase:
|
||||
|
||||
Time.new(2022, 1, 1, 1).strftime('%P') # => "am"
|
||||
Time.new(2022, 1, 1, 13).strftime('%P') # => "pm"
|
||||
|
||||
- <tt>%p</tt> - Meridian indicator, uppercase:
|
||||
|
||||
Time.new(2022, 1, 1, 1).strftime('%p') # => "AM"
|
||||
Time.new(2022, 1, 1, 13).strftime('%p') # => "PM"
|
||||
|
||||
- <tt>%M</tt> - Minute of the hour, in range (0..59), zero-padded:
|
||||
|
||||
Time.new(2022, 1, 1, 1, 0, 0).strftime('%M') # => "00"
|
||||
|
||||
- <tt>%S</tt> - Second of the minute in range (0..59), zero-padded:
|
||||
|
||||
Time.new(2022, 1, 1, 1, 0, 0, 0).strftime('%S') # => "00"
|
||||
|
||||
- <tt>%L</tt> - Millisecond of the second, in range (0..999), zero-padded:
|
||||
|
||||
Time.new(2022, 1, 1, 1, 0, 0, 0).strftime('%L') # => "000"
|
||||
|
||||
- <tt>%N</tt> - Fractional seconds, default width is 9 digits (nanoseconds):
|
||||
|
||||
t = Time.now # => 2022-06-29 07:10:20.3230914 -0500
|
||||
t.strftime('%N') # => "323091400" # Default.
|
||||
|
||||
Use {width specifiers}[rdoc-ref:strftime_formatting.rdoc@Width+Specifiers]
|
||||
to adjust units:
|
||||
|
||||
t.strftime('%3N') # => "323" # Milliseconds.
|
||||
t.strftime('%6N') # => "323091" # Microseconds.
|
||||
t.strftime('%9N') # => "323091400" # Nanoseconds.
|
||||
t.strftime('%12N') # => "323091400000" # Picoseconds.
|
||||
t.strftime('%15N') # => "323091400000000" # Femptoseconds.
|
||||
t.strftime('%18N') # => "323091400000000000" # Attoseconds.
|
||||
t.strftime('%21N') # => "323091400000000000000" # Zeptoseconds.
|
||||
t.strftime('%24N') # => "323091400000000000000000" # Yoctoseconds.
|
||||
|
||||
- <tt>%s</tt> - Number of seconds since the epoch:
|
||||
|
||||
Time.now.strftime('%s') # => "1656505136"
|
||||
|
||||
==== Timezone
|
||||
|
||||
- <tt>%z</tt> - Timezone as hour and minute offset from UTC:
|
||||
|
||||
Time.now.strftime('%z') # => "-0500"
|
||||
|
||||
- <tt>%Z</tt> - Timezone name (platform-dependent):
|
||||
|
||||
Time.now.strftime('%Z') # => "Central Daylight Time"
|
||||
|
||||
==== Weekday
|
||||
|
||||
- <tt>%A</tt> - Full weekday name:
|
||||
|
||||
Time.now.strftime('%A') # => "Wednesday"
|
||||
|
||||
- <tt>%a</tt> - Abbreviated weekday name:
|
||||
|
||||
Time.now.strftime('%a') # => "Wed"
|
||||
|
||||
- <tt>%u</tt> - Day of the week, in range (1..7), Monday is 1:
|
||||
|
||||
t = Time.new(2022, 6, 26) # => 2022-06-26 00:00:00 -0500
|
||||
t.strftime('%a') # => "Sun"
|
||||
t.strftime('%u') # => "7"
|
||||
|
||||
- <tt>%w</tt> - Day of the week, in range (0..6), Sunday is 0:
|
||||
|
||||
t = Time.new(2022, 6, 26) # => 2022-06-26 00:00:00 -0500
|
||||
t.strftime('%a') # => "Sun"
|
||||
t.strftime('%w') # => "0"
|
||||
|
||||
==== Week Number
|
||||
|
||||
- <tt>%U</tt> - Week number of the year, in range (0..53), zero-padded,
|
||||
where each week begins on a Sunday:
|
||||
|
||||
t = Time.new(2022, 6, 26) # => 2022-06-26 00:00:00 -0500
|
||||
t.strftime('%a') # => "Sun"
|
||||
t.strftime('%U') # => "26"
|
||||
|
||||
- <tt>%W</tt> - Week number of the year, in range (0..53), zero-padded,
|
||||
where each week begins on a Monday:
|
||||
|
||||
t = Time.new(2022, 6, 26) # => 2022-06-26 00:00:00 -0500
|
||||
t.strftime('%a') # => "Sun"
|
||||
t.strftime('%W') # => "25"
|
||||
|
||||
==== Week Dates
|
||||
|
||||
See {ISO 8601 week dates}[https://en.wikipedia.org/wiki/ISO_8601#Week_dates].
|
||||
|
||||
t0 = Time.new(2023, 1, 1) # => 2023-01-01 00:00:00 -0600
|
||||
t1 = Time.new(2024, 1, 1) # => 2024-01-01 00:00:00 -0600
|
||||
|
||||
- <tt>%G</tt> - Week-based year:
|
||||
|
||||
t0.strftime('%G') # => "2022"
|
||||
t1.strftime('%G') # => "2024"
|
||||
|
||||
- <tt>%g</tt> - Week-based year without century, in range (0..99), zero-padded:
|
||||
|
||||
t0.strftime('%g') # => "22"
|
||||
t1.strftime('%g') # => "24"
|
||||
|
||||
- <tt>%V</tt> - Week number of the week-based year, in range (1..53),
|
||||
zero-padded:
|
||||
|
||||
t0.strftime('%V') # => "52"
|
||||
t1.strftime('%V') # => "01"
|
||||
|
||||
==== Literals
|
||||
|
||||
- <tt>%n</tt> - Newline character "\n":
|
||||
|
||||
Time.now.strftime('%n') # => "\n"
|
||||
|
||||
- <tt>%t</tt> - Tab character "\t":
|
||||
|
||||
Time.now.strftime('%t') # => "\t"
|
||||
|
||||
- <tt>%%</tt> - Percent character '%':
|
||||
|
||||
Time.now.strftime('%%') # => "%"
|
||||
|
||||
==== Shorthand Conversion Specifiers
|
||||
|
||||
Each shorthand specifier here is shown with its corresponding
|
||||
longhand specifier.
|
||||
|
||||
- <tt>%c</tt> - \Date and time:
|
||||
|
||||
Time.now.strftime('%c') # => "Wed Jun 29 08:01:41 2022"
|
||||
Time.now.strftime('%a %b %e %T %Y') # => "Wed Jun 29 08:02:07 2022"
|
||||
|
||||
- <tt>%D</tt> - \Date:
|
||||
|
||||
Time.now.strftime('%D') # => "06/29/22"
|
||||
Time.now.strftime('%m/%d/%y') # => "06/29/22"
|
||||
|
||||
- <tt>%F</tt> - ISO 8601 date:
|
||||
|
||||
Time.now.strftime('%F') # => "2022-06-29"
|
||||
Time.now.strftime('%Y-%m-%d') # => "2022-06-29"
|
||||
|
||||
- <tt>%v</tt> - VMS date:
|
||||
|
||||
Time.now.strftime('%v') # => "29-JUN-2022"
|
||||
Time.now.strftime('%e-%^b-%4Y') # => "29-JUN-2022"
|
||||
|
||||
- <tt>%x</tt> - Same as <tt>%D</tt>.
|
||||
|
||||
- <tt>%X</tt> - Same as <tt>%T</tt>.
|
||||
|
||||
- <tt>%r</tt> - 12-hour time:
|
||||
|
||||
Time.new(2022, 1, 1, 1).strftime('%r') # => "01:00:00 AM"
|
||||
Time.new(2022, 1, 1, 1).strftime('%I:%M:%S %p') # => "01:00:00 AM"
|
||||
Time.new(2022, 1, 1, 13).strftime('%r') # => "01:00:00 PM"
|
||||
Time.new(2022, 1, 1, 13).strftime('%I:%M:%S %p') # => "01:00:00 PM"
|
||||
|
||||
- <tt>%R</tt> - 24-hour time:
|
||||
|
||||
Time.new(2022, 1, 1, 1).strftime('%R') # => "01:00"
|
||||
Time.new(2022, 1, 1, 1).strftime('%H:%M') # => "01:00"
|
||||
Time.new(2022, 1, 1, 13).strftime('%R') # => "13:00"
|
||||
Time.new(2022, 1, 1, 13).strftime('%H:%M') # => "13:00"
|
||||
|
||||
- <tt>%T</tt> - 24-hour time:
|
||||
|
||||
Time.new(2022, 1, 1, 1).strftime('%T') # => "01:00:00"
|
||||
Time.new(2022, 1, 1, 1).strftime('%H:%M:%S') # => "01:00:00"
|
||||
Time.new(2022, 1, 1, 13).strftime('%T') # => "13:00:00"
|
||||
Time.new(2022, 1, 1, 13).strftime('%H:%M:%S') # => "13:00:00"
|
||||
|
||||
- <tt>%+</tt> (not supported in Time#strftime) - \Date and time:
|
||||
|
||||
DateTime.now.strftime('%+')
|
||||
# => "Wed Jun 29 08:31:53 -05:00 2022"
|
||||
DateTime.now.strftime('%a %b %e %H:%M:%S %Z %Y')
|
||||
# => "Wed Jun 29 08:32:18 -05:00 2022"
|
||||
|
||||
=== ISO 8601 Format Specifications
|
||||
|
||||
This section shows format specifications that are compatible with
|
||||
{ISO 8601}[https://en.wikipedia.org/wiki/ISO_8601].
|
||||
Details for various formats may be seen at the links.
|
||||
|
||||
Examples in this section assume:
|
||||
|
||||
t = Time.now # => 2022-06-29 16:49:25.465246 -0500
|
||||
|
||||
==== Dates
|
||||
|
||||
See {ISO 8601 dates}[https://en.wikipedia.org/wiki/ISO_8601#Dates].
|
||||
|
||||
- {Years}[https://en.wikipedia.org/wiki/ISO_8601#Years]:
|
||||
|
||||
- Basic year (+YYYY+):
|
||||
|
||||
t.strftime('%Y') # => "2022"
|
||||
|
||||
- Expanded year (<tt>±YYYYY</tt>):
|
||||
|
||||
t.strftime('+%5Y') # => "+02022"
|
||||
t.strftime('-%5Y') # => "-02022"
|
||||
|
||||
- {Calendar dates}[https://en.wikipedia.org/wiki/ISO_8601#Calendar_dates]:
|
||||
|
||||
- Basic date (+YYYYMMDD+):
|
||||
|
||||
t.strftime('%Y%m%d') # => "20220629"
|
||||
|
||||
- Extended date (<tt>YYYY-MM-DD</tt>):
|
||||
|
||||
t.strftime('%Y-%m-%d') # => "2022-06-29"
|
||||
|
||||
- Reduced extended date (<tt>YYYY-MM</tt>):
|
||||
|
||||
t.strftime('%Y-%m') # => "2022-06"
|
||||
|
||||
- {Week dates}[https://en.wikipedia.org/wiki/ISO_8601#Week_dates]:
|
||||
|
||||
- Basic date (+YYYYWww+ or +YYYYWwwD+):
|
||||
|
||||
t.strftime('%Y%Ww') # => "202226w"
|
||||
t.strftime('%Y%Ww%u') # => "202226w3"
|
||||
|
||||
- Extended date (<tt>YYYY-Www</tt> or <tt>YYYY-Www-D<tt>):
|
||||
|
||||
t.strftime('%Y-%Ww') # => "2022-26w"
|
||||
t.strftime('%Y-%Ww-%u') # => "2022-26w-3"
|
||||
|
||||
- {Ordinal dates}[https://en.wikipedia.org/wiki/ISO_8601#Ordinal_dates]:
|
||||
|
||||
- Basic date (+YYYYDDD+):
|
||||
|
||||
t.strftime('%Y%j') # => "2022180"
|
||||
|
||||
- Extended date (<tt>YYYY-DDD</tt>):
|
||||
|
||||
t.strftime('%Y-%j') # => "2022-180"
|
||||
|
||||
==== Times
|
||||
|
||||
See {ISO 8601 times}[https://en.wikipedia.org/wiki/ISO_8601#Times].
|
||||
|
||||
- Times:
|
||||
|
||||
- Basic time (+Thhmmss.sss+, +Thhmmss+, +Thhmm+, or +Thh+):
|
||||
|
||||
t.strftime('T%H%M%S.%L') # => "T164925.465"
|
||||
t.strftime('T%H%M%S') # => "T164925"
|
||||
t.strftime('T%H%M') # => "T1649"
|
||||
t.strftime('T%H') # => "T16"
|
||||
|
||||
- Extended time (+Thh:mm:ss.sss+, +Thh:mm:ss+, or +Thh:mm+):
|
||||
|
||||
t.strftime('T%H:%M:%S.%L') # => "T16:49:25.465"
|
||||
t.strftime('T%H:%M:%S') # => "T16:49:25"
|
||||
t.strftime('T%H:%M') # => "T16:49"
|
||||
|
||||
- {Time zone designators}[https://en.wikipedia.org/wiki/ISO_8601#Time_zone_designators]:
|
||||
|
||||
- Timezone (+time+ represents a valid time,
|
||||
+hh+ represents a valid 2-digit hour,
|
||||
and +mm+ represents a valid 2-digit minute):
|
||||
|
||||
- Basic timezone (<tt>time±hhmm</tt>, <tt>time±hh</tt>, or +timeZ+):
|
||||
|
||||
t.strftime('T%H%M%S%z') # => "T164925-0500"
|
||||
t.strftime('T%H%M%S%z').slice(0..-3) # => "T164925-05"
|
||||
t.strftime('T%H%M%SZ') # => "T164925Z"
|
||||
|
||||
- Extended timezone (<tt>time±hh:mm</tt>):
|
||||
|
||||
t.strftime('T%H:%M:%S%z') # => "T16:49:25-0500"
|
||||
|
||||
- See also:
|
||||
|
||||
- {Local time (unqualified)}[https://en.wikipedia.org/wiki/ISO_8601#Local_time_(unqualified)].
|
||||
- {Coordinated Universal Time (UTC)}[https://en.wikipedia.org/wiki/ISO_8601#Coordinated_Universal_Time_(UTC)].
|
||||
- {Time offsets from UTC}[https://en.wikipedia.org/wiki/ISO_8601#Time_offsets_from_UTC].
|
||||
|
||||
==== Combined \Date and \Time
|
||||
|
||||
See {ISO 8601 Combined date and time representations}[https://en.wikipedia.org/wiki/ISO_8601#Combined_date_and_time_representations].
|
||||
|
||||
An ISO 8601 combined date and time representation may be any
|
||||
ISO 8601 date and any ISO 8601 time,
|
||||
separated by the letter +T+.
|
||||
|
||||
For the relevant +strftime+ formats, see
|
||||
{Dates}[rdoc-ref:strftime_formatting.rdoc@Dates]
|
||||
and {Times}[rdoc-ref:strftime_formatting.rdoc@Times] above.
|
||||
|
||||
=== Flags
|
||||
|
||||
Flags may affect certain formatting specifications.
|
||||
|
||||
Multiple flags may be given with a single conversion specified;
|
||||
order does not matter.
|
||||
|
||||
==== Padding Flags
|
||||
|
||||
- <tt>0</tt> - Pad with zeroes:
|
||||
|
||||
Time.new(10).strftime('%0Y') # => "0010"
|
||||
|
||||
- <tt>_</tt> - Pad with blanks:
|
||||
|
||||
Time.new(10).strftime('%_Y') # => " 10"
|
||||
|
||||
- <tt>-</tt> - Don't pad:
|
||||
|
||||
Time.new(10).strftime('%-Y') # => "10"
|
||||
|
||||
==== Casing Flags
|
||||
|
||||
- <tt>^</tt> - Upcase result:
|
||||
|
||||
Time.new(2022, 1).strftime('%B') # => "January" # No casing flag.
|
||||
Time.new(2022, 1).strftime('%^B') # => "JANUARY"
|
||||
|
||||
- <tt>#</tt> - Swapcase result:
|
||||
|
||||
Time.now.strftime('%p') # => "AM"
|
||||
Time.now.strftime('%^p') # => "AM"
|
||||
Time.now.strftime('%#p') # => "am"
|
||||
|
||||
==== Timezone Flags
|
||||
|
||||
- <tt>:</tt> - Put timezone as colon-separated hours and minutes:
|
||||
|
||||
Time.now.strftime('%:z') # => "-05:00"
|
||||
|
||||
- <tt>::</tt> - Put timezone as colon-separated hours, minutes, and seconds:
|
||||
|
||||
Time.now.strftime('%::z') # => "-05:00:00"
|
||||
|
||||
=== Width Specifiers
|
||||
|
||||
The integer width specifier gives a minimum width for the returned string:
|
||||
|
||||
Time.new(2002).strftime('%Y') # => "2002" # No width specifier.
|
||||
Time.new(2002).strftime('%10Y') # => "0000002002"
|
||||
Time.new(2002, 12).strftime('%B') # => "December" # No width specifier.
|
||||
Time.new(2002, 12).strftime('%10B') # => " December"
|
||||
Time.new(2002, 12).strftime('%3B') # => "December" # Ignored if too small.
|
||||
Loading…
Reference in a new issue