A JavaScript equivalent of PHP’s strptime
function strptime (dateStr, format) {
// http://kevin.vanzonneveld.net
// + original by: Brett Zamir (http://brett-zamir.me)
// + based on: strftime
// - depends on: setlocale
// - depends on: array_map
// * example 1: strptime('20091112222135', '%Y%m%d%H%M%S'); // Return value will depend on date and locale
// * returns 1: {tm_sec: 35, tm_min: 21, tm_hour: 22, tm_mday: 12, tm_mon: 10, tm_year: 109, tm_wday: 4, tm_yday: 315, unparsed: ''}
// * example 1: strptime('2009extra', '%Y');
// * returns 1: {tm_sec:0, tm_min:0, tm_hour:0, tm_mday:0, tm_mon:0, tm_year:109, tm_wday:3, tm_yday: -1, unparsed: 'extra'}
// tm_isdst is in other docs; why not PHP?
// Needs more thorough testing and examples
var retObj = {
tm_sec: 0,
tm_min: 0,
tm_hour: 0,
tm_mday: 0,
tm_mon: 0,
tm_year: 0,
tm_wday: 0,
tm_yday: 0,
unparsed: ''
},
that = this,
amPmOffset = 0,
prevHour = false,
_date = function () {
var o = retObj;
// We set date to at least 1 to ensure year or month doesn't go backwards
return _reset(new Date(Date.UTC(o.tm_year + 1900, o.tm_mon, o.tm_mday || 1, o.tm_hour, o.tm_min, o.tm_sec)), o.tm_mday);
},
_reset = function (dateObj, realMday) {
// realMday is to allow for a value of 0 in return results (but without
// messing up the Date() object)
var o = retObj;
var d = dateObj;
o.tm_sec = d.getUTCSeconds();
o.tm_min = d.getUTCMinutes();
o.tm_hour = d.getUTCHours();
o.tm_mday = realMday === 0 ? realMday : d.getUTCDate();
o.tm_mon = d.getUTCMonth();
o.tm_year = d.getUTCFullYear() - 1900;
o.tm_wday = realMday === 0 ? (d.getUTCDay() > 0 ? d.getUTCDay() - 1 : 6) : d.getUTCDay();
var jan1 = new Date(Date.UTC(d.getUTCFullYear(), 0, 1));
o.tm_yday = Math.ceil((d - jan1) / (1000 * 60 * 60 * 24));
};
// BEGIN STATIC
var _NWS = /\S/,
_WS = /\s/;
var _aggregates = {
c: 'locale',
D: '%m/%d/%y',
F: '%y-%m-%d',
r: 'locale',
R: '%H:%M',
T: '%H:%M:%S',
x: 'locale',
X: 'locale'
};
/* Fix: Locale alternatives are supported though not documented in PHP; see http://linux.die.net/man/3/strptime
Ec
EC
Ex
EX
Ey
EY
Od or Oe
OH
OI
Om
OM
OS
OU
Ow
OW
Oy
*/
var _preg_quote = function (str) {
return (str + '').replace(/([\\\.\+\*\?\[\^\]\$\(\)\{\}\=\!<>\|\:])/g, '\\$1');
};
// END STATIC
// BEGIN REDUNDANT
this.php_js = this.php_js || {};
this.setlocale('LC_ALL', 0); // ensure setup of localization variables takes place
// END REDUNDANT
var phpjs = this.php_js;
var locale = phpjs.localeCategories.LC_TIME;
var locales = phpjs.locales;
var lc_time = locales[locale].LC_TIME;
// First replace aggregates (run in a loop because an agg may be made up of other aggs)
while (format.match(/%[cDFhnrRtTxX]/)) {
format = format.replace(/%([cDFhnrRtTxX])/g, function (m0, m1) {
var f = _aggregates[m1];
return (f === 'locale' ? lc_time[m1] : f);
});
}
var _addNext = function (j, regex, cb) {
if (typeof regex === 'string') {
regex = new RegExp('^' + regex, 'i');
}
var check = dateStr.slice(j);
var match = regex.exec(check);
// Even if the callback returns null after assigning to the return object, the object won't be saved anyways
var testNull = match ? cb.apply(null, match) : null;
if (testNull === null) {
throw 'No match in string';
}
return j + match[0].length;
};
var _addLocalized = function (j, formatChar, category) {
return _addNext(j, that.array_map(
_preg_quote, lc_time[formatChar]).join('|'), // Could make each parenthesized instead and pass index to callback
function (m) {
var match = lc_time[formatChar].search(new RegExp('^' + _preg_quote(m) + '$', 'i'));
if (match) {
retObj[category] = match[0];
}
});
};
// BEGIN PROCESSING CHARACTERS
for (var i = 0, j = 0; i < format.length; i++) {
if (format.charAt(i) === '%') {
var literalPos = ['%', 'n', 't'].indexOf(format.charAt(i + 1));
if (literalPos !== -1) {
if (['%', '\n', '\t'].indexOf(dateStr.charAt(j)) === literalPos) { // a matched literal
++i, ++j; // skip beyond
continue;
}
// Format indicated a percent literal, but not actually present
return false;
}
var formatChar = format.charAt(i + 1);
try {
switch (formatChar) {
case 'a':
// Fall-through // Sun-Sat
case 'A':
// Sunday-Saturday
j = _addLocalized(j, formatChar, 'tm_wday'); // Changes nothing else
break;
case 'h':
// Fall-through (alias of 'b');
case 'b':
// Jan-Dec
j = _addLocalized(j, 'b', 'tm_mon');
_date(); // Also changes wday, yday
break;
case 'B':
// January-December
j = _addLocalized(j, formatChar, 'tm_mon');
_date(); // Also changes wday, yday
break;
case 'C':
// 0+; century (19 for 20th)
j = _addNext(j, /^\d?\d/, // PHP docs say two-digit, but accepts one-digit (two-digit max)
function (d) {
var year = (parseInt(d, 10) - 19) * 100;
retObj.tm_year = year;
_date();
if (!retObj.tm_yday) {
retObj.tm_yday = -1;
}
// Also changes wday; and sets yday to -1 (always?)
});
break;
case 'd':
// Fall-through 01-31 day
case 'e':
// 1-31 day
j = _addNext(j, formatChar === 'd' ? /^(0[1-9]|[1-2]\d|3[0-1])/ : /^([1-2]\d|3[0-1]|[1-9])/, function (d) {
var dayMonth = parseInt(d, 10);
retObj.tm_mday = dayMonth;
_date(); // Also changes w_day, y_day
});
break;
case 'g':
// No apparent effect; 2-digit year (see 'V')
break;
case 'G':
// No apparent effect; 4-digit year (see 'V')'
break;
case 'H':
// 00-23 hours
j = _addNext(j, /^([0-1]\d|2[0-3])/, function (d) {
var hour = parseInt(d, 10);
retObj.tm_hour = hour;
// Changes nothing else
});
break;
case 'l':
// Fall-through of lower-case 'L'; 1-12 hours
case 'I':
// 01-12 hours
j = _addNext(j, formatChar === 'l' ? /^([1-9]|1[0-2])/ : /^(0[1-9]|1[0-2])/, function (d) {
var hour = parseInt(d, 10) - 1 + amPmOffset;
retObj.tm_hour = hour;
prevHour = true; // Used for coordinating with am-pm
// Changes nothing else, but affected by prior 'p/P'
});
break;
case 'j':
// 001-366 day of year
j = _addNext(j, /^(00[1-9]|0[1-9]\d|[1-2]\d\d|3[0-6][0-6])/, function (d) {
var dayYear = parseInt(d, 10) - 1;
retObj.tm_yday = dayYear;
// Changes nothing else (oddly, since if based on a given year, could calculate other fields)
});
break;
case 'm':
// 01-12 month
j = _addNext(j, /^(0[1-9]|1[0-2])/, function (d) {
var month = parseInt(d, 10) - 1;
retObj.tm_mon = month;
_date(); // Also sets wday and yday
});
break;
case 'M':
// 00-59 minutes
j = _addNext(j, /^[0-5]\d/, function (d) {
var minute = parseInt(d, 10);
retObj.tm_min = minute;
// Changes nothing else
});
break;
case 'P':
// Seems not to work; AM-PM
return false; // Could make fall-through instead since supposed to be a synonym despite PHP docs
case 'p':
// am-pm
j = _addNext(j, /^(am|pm)/i, function (d) {
// No effect on 'H' since already 24 hours but
// works before or after setting of l/I hour
amPmOffset = (/a/).test(d) ? 0 : 12;
if (prevHour) {
retObj.tm_hour += amPmOffset;
}
});
break;
case 's':
// Unix timestamp (in seconds)
j = _addNext(j, /^\d+/, function (d) {
var timestamp = parseInt(d, 10);
var date = new Date(Date.UTC(timestamp * 1000));
_reset(date);
// Affects all fields, but can't be negative (and initial + not allowed)
});
break;
case 'S':
// 00-59 seconds
j = _addNext(j, /^[0-5]\d/, // strptime also accepts 60-61 for some reason
function (d) {
var second = parseInt(d, 10);
retObj.tm_sec = second;
// Changes nothing else
});
break;
case 'u':
// Fall-through; 1 (Monday)-7(Sunday)
case 'w':
// 0 (Sunday)-6(Saturday)
j = _addNext(j, /^\d/, function (d) {
retObj.tm_wday = d - (formatChar === 'u');
// Changes nothing else apparently
});
break;
case 'U':
// Fall-through (week of year, from 1st Sunday)
case 'V':
// Fall-through (ISO-8601:1988 week number; from first 4-weekday week, starting with Monday)
case 'W':
// Apparently ignored (week of year, from 1st Monday)
break;
case 'y':
// 69 (or higher) for 1969+, 68 (or lower) for 2068-
j = _addNext(j, /^\d?\d/, // PHP docs say two-digit, but accepts one-digit (two-digit max)
function (d) {
d = parseInt(d, 10);
var year = d >= 69 ? d : d + 100;
retObj.tm_year = year;
_date();
if (!retObj.tm_yday) {
retObj.tm_yday = -1;
}
// Also changes wday; and sets yday to -1 (always?)
});
break;
case 'Y':
// 2010 (4-digit year)
j = _addNext(j, /^\d{1,4}/, // PHP docs say four-digit, but accepts one-digit (four-digit max)
function (d) {
var year = (parseInt(d, 10)) - 1900;
retObj.tm_year = year;
_date();
if (!retObj.tm_yday) {
retObj.tm_yday = -1;
}
// Also changes wday; and sets yday to -1 (always?)
});
break;
case 'z':
// Timezone; on my system, strftime gives -0800, but strptime seems not to alter hour setting
break;
case 'Z':
// Timezone; on my system, strftime gives PST, but strptime treats text as unparsed
break;
default:
throw 'Unrecognized formatting character in strptime()';
break;
}
} catch (e) {
if (e === 'No match in string') { // Allow us to exit
return false; // There was supposed to be a matching format but there wasn't
}
}++i; // Calculate skipping beyond initial percent too
} else if (format.charAt(i) !== dateStr.charAt(j)) {
// If extra whitespace at beginning or end of either, or between formats, no problem
// (just a problem when between % and format specifier)
// If the string has white-space, it is ok to ignore
if (dateStr.charAt(j).search(_WS) !== -1) {
j++;
i--; // Let the next iteration try again with the same format character
} else if (format.charAt(i).search(_NWS) !== -1) { // Any extra formatting characters besides white-space causes
// problems (do check after WS though, as may just be WS in string before next character)
return false;
} else { // Extra WS in format
// Adjust strings when encounter non-matching whitespace, so they align in future checks above
// Will check on next iteration (against same (non-WS) string character)
}
} else {
j++;
}
}
// POST-PROCESSING
retObj.unparsed = dateStr.slice(j); // Will also get extra whitespace; empty string if none
return retObj;
}
Example 1
strptime('20091112222135', '%Y%m%d%H%M%S'); // Return value will depend on date and locale
strptime('2009extra', '%Y');
Should return
{tm_sec: 35, tm_min: 21, tm_hour: 22, tm_mday: 12, tm_mon: 10, tm_year: 109, tm_wday: 4, tm_yday: 315, unparsed: ''}
{tm_sec:0, tm_min:0, tm_hour:0, tm_mday:0, tm_mon:0, tm_year:109, tm_wday:3, tm_yday: -1, unparsed: 'extra'}