PHP 8.4.0 RC2 available for testing

Supported Date and Time Formats

This section describes all the different formats in a BNF-like format, that the DateTimeImmutable, DateTime, date_create_immutable(), date_create(), date_parse(), and strtotime() parser understands. The formats are grouped by section. In most cases formats from different sections, separated by whitespace, comma or dot, can be used in the same date/time string. For each of the supported formats, one or more examples are given, as well as a description for the format. Characters in single quotes in the formats are case-insensitive ('t' could be t or T), characters in double quotes are case-sensitive ("T" is only T).

To format DateTimeImmutable and DateTime objects, please refer to the documentation of the DateTimeInterface::format() method.

A general set of rules should be taken into account.

  1. The parser, allows for each unit (year, month, day, hour, minute, second) the full range of values. For a year that's just 4 digits, for a month that's 0-12, day is 0-31, hour is 0-24, and minute is 0-59.
  2. 60 is allowed for seconds, as sometimes date strings with that leapsecond do show up. But PHP implements Unix time where "60" is not a valid second number and hence it overflows.
  3. strtotime() returns false if any number is outside of the ranges, and DateTimeImmutable::__construct() throws an exception.
  4. If a string contains a date, all time elements are reset to 0.
  5. All less-significant time elements are reset to 0 if any part of a time is present in the given string.
  6. The parser is dumb, and doesn't do any checks to make it faster (and more generic).
  7. Besides rules for individual time elements, the parser also understand more specific compound formats, such as parsing Unix timestamps (@1690388256) and ISO Weekdates (2008-W28-3).
  8. There is an additional check if an invalid date is provided:

    <?php
    $res
    = date_parse("2015-09-31");
    var_dump($res["warnings"]);
    ?>

    以上示例会输出:

    array(1) {
      [11] =>
      string(27) "The parsed date was invalid"
    }
    

  9. It is already possible to handle the edge cases, but then DateTimeImmutable::createFromFormat() must be used while supplying the correct format.

    <?php
    $res
    = DateTimeImmutable::createFromFormat("Y-m-d", "2015-09-34");
    var_dump($res);

    以上示例会输出:

    object(DateTimeImmutable)#1 (3) {
      ["date"]=>
      string(26) "2015-10-04 17:24:43.000000"
      ["timezone_type"]=>
      int(3)
      ["timezone"]=>
      string(13) "Europe/London"
    }
    

Time Formats

This page describes the different date/time formats in a BNF-like syntax, that the DateTimeImmutable, DateTime, date_create(), date_create_immutable(), and strtotime() parser understands.

To format DateTimeImmutable and DateTime objects, please refer to the documentation of the DateTimeInterface::format() method.

Used Symbols
Description Formats Examples
frac . [0-9]+ ".21342", ".85"
hh "0"?[1-9] | "1"[0-2] "04", "7", "12"
HH [01][0-9] | "2"[0-4] "04", "07", "19"
meridian [AaPp] .? [Mm] .? [\0\t ] "A.m.", "pM", "am."
MM [0-5][0-9] "00", "12", "59"
II [0-5][0-9] "00", "12", "59"
space [ \t]  
tz "("? [A-Za-z]{1,6} ")"? | [A-Z][a-z]+([_/][A-Z][a-z]+)+ "CEST", "Europe/Amsterdam", "America/Indiana/Knox"
tzcorrection "GMT"? [+-] hh ":"? MM? "+0400", "GMT-07:00", "-07:00"
12 Hour Notation
Description Format Examples
Hour only, with meridian hh space? meridian "4 am", "5PM"
Hour and minutes, with meridian hh [.:] MM space? meridian "4:08 am", "7:19P.M."
Hour, minutes and seconds, with meridian hh [.:] MM [.:] II space? meridian "4:08:37 am", "7:19:19P.M."
MS SQL (Hour, minutes, seconds and fraction with meridian) hh ":" MM ":" II [.:] [0-9]+ meridian "4:08:39:12313am"
24 Hour Notation
Description Format Examples
Hour and minutes 't'? HH [.:] MM "04:08", "19.19", "T23:43"
Hour and minutes, no colon 't'? HH MM "0408", "t1919", "T2343"
Hour, minutes and seconds 't'? HH [.:] MM [.:] II "04.08.37", "t19:19:19"
Hour, minutes and seconds, no colon 't'? HH MM II "040837", "T191919"
Hour, minutes, seconds and timezone 't'? HH [.:] MM [.:] II space? ( tzcorrection | tz ) "040837CEST", "T191919-0700"
Hour, minutes, seconds and fraction 't'? HH [.:] MM [.:] II frac "04.08.37.81412", "19:19:19.532453"
Time zone information tz | tzcorrection "CEST", "Europe/Amsterdam", "+0430", "GMT-06:00"

Date Formats

This page describes the different date formats in a BNF-like syntax, that the DateTimeImmutable, DateTime, date_create(), date_create_immutable(), and strtotime() parser understands.

To format DateTimeImmutable and DateTime objects, please refer to the documentation of the DateTimeInterface::format() method.

Used Symbols
Description Format Examples
daysuf "st" | "nd" | "rd" | "th"  
dd ([0-2]?[0-9] | "3"[01]) daysuf? "7th", "22nd", "31"
DD "0" [0-9] | [1-2][0-9] | "3" [01] "07", "31"
m 'january' | 'february' | 'march' | 'april' | 'may' | 'june' | 'july' | 'august' | 'september' | 'october' | 'november' | 'december' | 'jan' | 'feb' | 'mar' | 'apr' | 'may' | 'jun' | 'jul' | 'aug' | 'sep' | 'sept' | 'oct' | 'nov' | 'dec' | "I" | "II" | "III" | "IV" | "V" | "VI" | "VII" | "VIII" | "IX" | "X" | "XI" | "XII"  
M 'jan' | 'feb' | 'mar' | 'apr' | 'may' | 'jun' | 'jul' | 'aug' | 'sep' | 'sept' | 'oct' | 'nov' | 'dec'  
mm "0"? [0-9] | "1"[0-2] "0", "04", "7", "12"
MM "0" [0-9] | "1"[0-2] "00", "04", "07", "12"
y [0-9]{1,4} "00", "78", "08", "8", "2008"
yy [0-9]{2} "00", "08", "78"
YY [0-9]{4} "2000", "2008", "1978"
YYY [0-9]{5,19} "81412", "20192"
Localized Notations
Description Format Examples
American month and day mm "/" dd "5/12", "10/27"
American month, day and year mm "/" dd "/" y "12/22/78", "1/17/2006", "1/17/6"
Four digit year, month and day with slashes YY "/" mm "/" dd "2008/6/30", "1978/12/22"
Four digit year and month (GNU) YY "-" mm "2008-6", "2008-06", "1978-12"
Year, month and day with dashes y "-" mm "-" dd "2008-6-30", "78-12-22", "8-6-21"
Day, month and four digit year, with dots, tabs or dashes dd [.\t-] mm [.-] YY "30-6-2008", "22.12.1978"
Day, month and two digit year, with dots or tabs dd [.\t] mm "." yy "30.6.08", "22\t12.78"
Day, textual month and year dd ([ \t.-])* m ([ \t.-])* y "30-June 2008", "22DEC78", "14 III 1879"
Textual month and four digit year (Day reset to 1) m ([ \t.-])* YY "June 2008", "DEC1978", "March 1879"
Four digit year and textual month (Day reset to 1) YY ([ \t.-])* m "2008 June", "1978-XII", "1879.MArCH"
Textual month, day and year m ([ .\t-])* dd [,.stndrh\t ]+ y "July 1st, 2008", "April 17, 1790", "May.9,78"
Textual month and day m ([ .\t-])* dd [,.stndrh\t ]* "July 1st,", "Apr 17", "May.9"
Day and textual month dd ([ .\t-])* m "1 July", "17 Apr", "9.May"
Month abbreviation, day and year M "-" DD "-" y "May-09-78", "Apr-17-1790"
Year, month abbreviation and day y "-" M "-" DD "78-Dec-22", "1814-MAY-17"
Year (and just the year) YY "1978", "2008"
Year (expanded, 5-19 digits with sign) [+-] YYY "-81120", "+20192"
Textual month (and just the month) m "March", "jun", "DEC"
ISO8601 Notations
Description Format Examples
Eight digit year, month and day YY MM DD "15810726", "19780417", "18140517"
Four digit year, month and day with slashes YY "/" MM "/" DD "2008/06/30", "1978/12/22"
Two digit year, month and day with dashes yy "-" MM "-" DD "08-06-30", "78-12-22"
Four digit year with optional sign, month and day [+-]? YY "-" MM "-" DD "-0002-07-26", "+1978-04-17", "1814-05-17"
Five+ digit year with required sign, month and day [+-] YYY "-" MM "-" DD "-81120-02-26", "+20192-04-17"

注意:

For the y and yy formats, years below 100 are handled in a special way when the y or yy symbol is used. If the year falls in the range 0 (inclusive) to 69 (inclusive), 2000 is added. If the year falls in the range 70 (inclusive) to 99 (inclusive) then 1900 is added. This means that "00-01-01" is interpreted as "2000-01-01".

注意:

The "Day, month and two digit year, with dots or tabs" format (dd [.\t] mm "." yy) only works for the year values 61 (inclusive) to 99 (inclusive) - outside those years the time format "HH [.:] MM [.:] SS" has precedence.

注意:

The "Year (and just the year)" format only works if a time string has already been found -- otherwise this format is recognised as HH MM.

警告

It is possible to over- and underflow the dd and DD format. Day 0 means the last day of previous month, whereas overflows count into the next month. This makes "2008-08-00" equivalent to "2008-07-31" and "2008-06-31" equivalent to "2008-07-01" (June only has 30 days).

Note that the day range is restricted to 0-31 as indicated by the regular expression above. Thus "2008-06-32" is not a valid date string, for instance.

It is also possible to underflow the mm and MM formats with the value 0. A month value of 0 means December of the previous year. As example "2008-00-22" is equivalent to "2007-12-22".

If you combine the previous two facts and underflow both the day and the month, the following happens: "2008-00-00" first gets converted to "2007-12-00" which then gets converted to "2007-11-30". This also happens with the string "0000-00-00", which gets transformed into "-0001-11-30" (the year -1 in the ISO 8601 calendar, which is 2 BC in the proleptic Gregorian calendar).

Compound Formats

This page describes the different compound date/time formats in a BNF-like syntax, that the DateTimeImmutable, DateTime, date_create(), date_create_immutable(), and strtotime() parser understands.

To format DateTimeImmutable and DateTime objects, please refer to the documentation of the DateTimeInterface::format() method.

Used Symbols
Description Formats Examples
DD "0" [0-9] | [1-2][0-9] | "3" [01] "02", "12", "31"
doy "00"[1-9] | "0"[1-9][0-9] | [1-2][0-9][0-9] | "3"[0-5][0-9] | "36"[0-6] "001", "012", "180", "350", "366"
frac . [0-9]+ ".21342", ".85"
hh "0"?[1-9] | "1"[0-2] "04", "7", "12"
HH [01][0-9] | "2"[0-4] "04", "07", "19"
meridian [AaPp] .? [Mm] .? [\0\t ] "A.m.", "pM", "am."
ii [0-5]?[0-9] "04", "8", "59"
II [0-5][0-9] "04", "08", "59"
M 'jan' | 'feb' | 'mar' | 'apr' | 'may' | 'jun' | 'jul' | 'aug' | 'sep' | 'sept' | 'oct' | 'nov' | 'dec'  
MM [0-1][0-9] "00", "12"
space [ \t]  
ss ([0-5]?[0-9])|60 "04", "8", "59", "60" (leap second)
SS [0-5][0-9] "04", "08", "59"
W "0"[1-9] | [1-4][0-9] | "5"[0-3] "05", "17", "53"
tzcorrection "GMT"? [+-] hh ":"? II? "+0400", "GMT-07:00", "-07:00"
YY [0-9]{4} "2000", "2008", "1978"
Standards Formats
Description Examples
ATOM "2022-06-02T16:58:35+00:00"
COOKIE "Thursday, 02-Jun-2022 16:58:35 UTC"
ISO8601 "2022-06-02T16:58:35+0000"
» RFC 822 "Thu, 02 Jun 22 16:58:35 +0000"
» RFC 850 "Thursday, 02-Jun-22 16:58:35 UTC"
» RFC 1036 "Thu, 02 Jun 22 16:58:35 +0000"
» RFC 1123 "Thu, 02 Jun 2022 16:58:35 +0000"
» RFC 2822 "Thu, 02 Jun 2022 16:58:35 +0000"
» RFC 3339 "2022-06-02T16:58:35+00:00"
» RFC 3339 Extended "2022-06-02T16:58:35.698+00:00"
» RFC 7231 "Thu, 02 Jun 2022 16:58:35 GMT"
RSS "Thu, 02 Jun 2022 16:58:35 +0000"
W3C "2022-06-02T16:58:35+00:00"
Localized Notations
Description Format Examples
Common Log Format dd "/" M "/" YY : HH ":" II ":" SS space tzcorrection "10/Oct/2000:13:55:36 -0700"
EXIF YY ":" MM ":" DD " " HH ":" II ":" SS "2008:08:07 18:11:31"
ISO year with ISO week YY "-"? "W" W "2008W27", "2008-W28"
ISO year with ISO week and day YY "-"? "W" W "-"? [0-7] "2008W273", "2008-W28-3"
MySQL YY "-" MM "-" DD " " HH ":" II ":" SS "2008-08-07 18:11:31"
PostgreSQL: Year with day-of-year YY "."? doy "2008.197", "2008197"
SOAP YY "-" MM "-" DD "T" HH ":" II ":" SS frac tzcorrection? "2008-07-01T22:35:17.02", "2008-07-01T22:35:17.03+08:00"
Unix Timestamp "@" "-"? [0-9]+ "@1215282385"
Unix Timestamp with microseconds "@" "-"? [0-9]+ "." [0-9]{0,6} "@1607974647.503686"
XMLRPC YY MM DD "T" hh ":" II ":" SS "20080701T22:38:07", "20080701T9:38:07"
XMLRPC (Compact) YY MM DD 't' hh II SS "20080701t223807", "20080701T093807"
WDDX YY "-" mm "-" dd "T" hh ":" ii ":" ss "2008-7-1T9:3:37"

注意:

The "W" in the "ISO year with ISO week" and "ISO year with ISO week and day" formats is case-sensitive, you can only use the upper case "W".

The "T" in the SOAP, XMLRPC and WDDX formats is case-sensitive, you can only use the upper case "T".

The "Unix Timestamp" format sets the timezone to UTC.

Relative Formats

This page describes the different relative date/time formats in a BNF-like syntax, that the DateTimeImmutable, DateTime, date_create(), date_create_immutable(), and strtotime() parser understands.

To format DateTimeImmutable and DateTime objects, please refer to the documentation of the DateTimeInterface::format() method.

Used Symbols
Description Format
dayname 'sunday' | 'monday' | 'tuesday' | 'wednesday' | 'thursday' | 'friday' | 'saturday' | 'sun' | 'mon' | 'tue' | 'wed' | 'thu' | 'fri' | 'sat'
daytext 'weekday' | 'weekdays'
number [+-]?[0-9]+
ordinal 'first' | 'second' | 'third' | 'fourth' | 'fifth' | 'sixth' | 'seventh' | 'eighth' | 'ninth' | 'tenth' | 'eleventh' | 'twelfth' | 'next' | 'last' | 'previous' | 'this'
reltext 'next' | 'last' | 'previous' | 'this'
space [ \t]+
unit 'ms' | 'µs' | (( 'msec' | 'millisecond' | 'µsec' | 'microsecond' | 'usec' | 'sec' | 'second' | 'min' | 'minute' | 'hour' | 'day' | 'fortnight' | 'forthnight' | 'month' | 'year') 's'?) | 'weeks' | daytext
Day-based Notations
Format Description Examples
'yesterday' Midnight of yesterday "yesterday 14:00"
'midnight' The time is set to 00:00:00  
'today' The time is set to 00:00:00  
'now' Now - this is simply ignored  
'noon' The time is set to 12:00:00 "yesterday noon"
'tomorrow' Midnight of tomorrow  
'back of' hour 15 minutes past the specified hour "back of 7pm", "back of 15"
'front of' hour 15 minutes before the specified hour "front of 5am", "front of 23"
'first day of' Sets the day of the first of the current month. This phrase is usually best used together with a month name following it as it only effects the current month "first day of January 2008"
'last day of' Sets the day to the last day of the current month. This phrase is usually best used together with a month name following it as it only effects the current month "last day of next month"
ordinal space dayname space 'of' Calculates the x-th week day of the current month. "first sat of July 2008"
'last' space dayname space 'of' Calculates the last week day of the current month. "last sat of July 2008"
number space? (unit | 'week') Handles relative time items where the value is a number. "+5 weeks", "12 day", "-7 weekdays"
(ordinal | reltext) space unit Handles relative time items where the value is text. last and previous are equivalent to -1, this to nothing, and next to +1. "fifth day", "second month", "last day", "previous year"
'ago' Negates all the values of previously found relative time items. "2 days ago", "8 days ago 14:00", "2 months 5 days ago", "2 months ago 5 days", "2 days ago"
dayname Moves to the next day of this name. (See note) "Monday"
reltext space 'week' Handles the special format "weekday + last/this/next week". "Monday next week"

注意:

Relative statements are always processed after non-relative statements. This makes "+1 week july 2008" and "july 2008 +1 week" equivalent.

Exceptions to this rule are: "yesterday", "midnight", "today", "noon" and "tomorrow". Note that "tomorrow 11:00" and "11:00 tomorrow" are different. Considering today's date of "July 23rd, 2008" the first one produces "2008-07-24 11:00" where as the second one produces "2008-07-24 00:00". The reason for this is that those five statements directly influence the current time.

Keywords such as "first day of" depend on the context in which the relative format string is used. If used with a static method or function, the referent is the current system timestamp. However, if used in DateTime::modify() or DateTimeImmutable::modify(), the referent is the object on which the modify() method is called.

注意:

Observe the following remarks when the current day-of-week is the same as the day-of-week used in the date/time string. The current day-of-week could have been (re-)calculated by non-relative parts of the date/time string however.

  1. "dayname" does not advance to another day. (Example: "Wed July 23rd, 2008" means "2008-07-23").
  2. "number dayname" does not advance to another day. (Example: "1 wednesday july 23rd, 2008" means "2008-07-23").
  3. "number week dayname" will first add the number of weeks, but does not advance to another day. In this case "number week" and "dayname" are two distinct blocks. (Example: "+1 week wednesday july 23rd, 2008" means "2008-07-30").
  4. "ordinal dayname" does advance to another day. (Example "first wednesday july 23rd, 2008" means "2008-07-30").
  5. "number week ordinal dayname" will first add the number of weeks, and then advances to another day. In this case "number week" and "ordinal dayname" are two distinct blocks. (Example: "+1 week first wednesday july 23rd, 2008" means "2008-08-06").
  6. "ordinal dayname 'of' " does not advance to another day. (Example: "first wednesday of july 23rd, 2008" means "2008-07-02" because the specific phrase with 'of' resets the day-of-month to '1' and the '23rd' is ignored here).

Also observe that the "of" in "ordinal space dayname space 'of' " and "'last' space dayname space 'of' " does something special.

  1. It sets the day-of-month to 1.
  2. "ordinal dayname 'of' " does not advance to another day. (Example: "first tuesday of july 2008" means "2008-07-01").
  3. "ordinal dayname " does advance to another day. (Example: "first tuesday july 2008" means "2008-07-08", see also point 4 in the list above).
  4. "'last' dayname 'of' " takes the last dayname of the current month. (Example: "last wed of july 2008" means "2008-07-30")
  5. "'last' dayname" takes the last dayname from the current day. (Example: "last wed july 2008" means "2008-06-25"; "july 2008" first sets the current date to "2008-07-01" and then "last wed" moves to the previous Wednesday which is "2008-06-25").

注意:

Relative month values are calculated based on the length of months that they pass through. An example would be "+2 month 2011-11-30", which would produce "2012-01-30". This is due to November being 30 days in length, and December being 31 days in length, producing a total of 61 days.

注意:

number is an integer number; if a decimal number is given, the dot (or comma) is likely interpreted as delimiter. For instance, '+1.5 hours' is parsed like '+1 5 hours', not as '+1 hour +30 minutes'.

更新日志

版本 说明
8.2.0 number no longer accepts multiple signs, e.g. +-2.
7.0.8 Weeks always start on monday. Formerly, sunday would also be considered to start a week.

add a note

User Contributed Notes 2 notes

up
2
Anonymous
1 month ago
The year-only format is a potential issue that could cause problems for you.

<?php
echo (new DateTime('1994'))->format('Y-m-d');
// Outputs today's date in the year 1984, e.g. "1994-08-15"
echo (new DateTime('2004'))->format('Y-m-d');
// Outputs today's date in the *current* year, e.g. "2024-08-15"
?>

This is because, as noted above in the documentation, 2004 gets interpreted as a time, e.g. 20:04, rather than as a year. Even though 1994 is interpreted as a year.

One solution is to add ' T' to the end of the string:

<?php
echo (new DateTime('1994 T'))->format('Y-m-d');
// "1994-08-15"
echo (new DateTime('2004 T'))->format('Y-m-d');
// "2004-08-15"
?>

Another would be to add an arbitrary time to the beginning of the string:

<?php
echo (new DateTime('11:00 1994'))->format('Y-m-d');
// "1994-08-15"
echo (new DateTime('11:00 2004'))->format('Y-m-d');
// "2004-08-15"
?>
up
1
Anonymous
19 days ago
I wrote previously that appending a 'T' to a year forces PHP to interpret the date as a year rather than a time. This does not appear to be universally true. While this method did work for me in my previous development environment (PHP 8.1 on Ubuntu 20.04), it does not work after upgrading my development environment (PHP 8.3 on Ubuntu 24.04). The 'T' is instead seen as a timezone.

Further testing shows that PHP 8.1 (and even earlier PHP versions) also have this new behavior I am observing. Therefore, I can only assume the behavior is dependent on environment and/or build rather than PHP version.

The suggestion about adding an actual time string to the year, e.g. '00:00 2004', is still valid. This appears to be the only reliable way to force PHP to interpret a string as a date rather than a datetime.
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