This page describes the different date formats that the strtotime(), DateTime and date_create() parser understands.
| 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" |
| 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\t1978" |
| Day, month and two digit year, with dots or tabs | dd [.\t] mm "." yy | "30.6.08", "22\t12\t78" |
| 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 | d ([ .\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" |
| Textual month (and just the month) | m | "March", "jun", "DEC" |
| 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" |
Note:
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".
Note:
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.
Note:
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.
Note:
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).
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).
Note: the day (dd or DD) is first checked for range 0..31 and only if it fits, the overflow and underflow mechanism may apply. If not, strtotime() simply returns false.
If you need unlimited over/underflow for date calculations (for example 2015-01-40 to 2015-02-09), use mktime() instead.
It's important to note that strtotime does NOT successfully handle any date/time format with the word 'at' in it. (Commonly used.) ie:
September 15th at 6:12 PM
It also does not handle any date/time format with brackets (also reasonably common).
September 15th (6:12:14 PM)
To get around this, and create a more universally compatible strtotime, create your own custom strtotime which first filters these out with a str_replace.
function fullstrtotime ($time) {
return strtotime(str_replace(array(" at", "(", ")"), "", $time));
}
Note: the day (dd or DD) is first checked for range 0..31 and only if it fits, the overflow and underflow mechanism may apply. If not, strtotime() simply returns false.
If you need unlimited over/underflow for date calculations (for example 2015-01-40 to 2015-02-09), use mktime() instead.
If you use one of the "textual month + day" formats (like "July 1st" or "17 Apr"), current year is assumed.
