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-
- /**
- * Module exports.
- */
-
- module.exports = weekdayRange;
-
- /**
- * Only the first parameter is mandatory. Either the second, the third, or both
- * may be left out.
- *
- * If only one parameter is present, the function yeilds a true value on the
- * weekday that the parameter represents. If the string "GMT" is specified as
- * a second parameter, times are taken to be in GMT, otherwise in local timezone.
- *
- * If both wd1 and wd1 are defined, the condition is true if the current weekday
- * is in between those two weekdays. Bounds are inclusive. If the "GMT" parameter
- * is specified, times are taken to be in GMT, otherwise the local timezone is
- * used.
- *
- * Valid "weekday strings" are:
- *
- * SUN MON TUE WED THU FRI SAT
- *
- * Examples:
- *
- * ``` js
- * weekdayRange("MON", "FRI")
- * true Monday trhough Friday (local timezone).
- *
- * weekdayRange("MON", "FRI", "GMT")
- * same as above, but GMT timezone.
- *
- * weekdayRange("SAT")
- * true on Saturdays local time.
- *
- * weekdayRange("SAT", "GMT")
- * true on Saturdays GMT time.
- *
- * weekdayRange("FRI", "MON")
- * true Friday through Monday (note, order does matter!).
- * ```
- *
- *
- * @param {String} wd1 one of the weekday strings.
- * @param {String} wd2 one of the weekday strings.
- * @param {String} gmt is either the string: GMT or is left out.
- * @return {Boolean}
- */
-
- const dayOrder = { "SUN": 0, "MON": 1, "TUE": 2, "WED": 3, "THU": 4, "FRI": 5, "SAT": 6 };
-
- function weekdayRange (wd1, wd2, gmt) {
-
- var useGMTzone = (wd2 == "GMT" || gmt == "GMT"),
- todaysDay = getTodaysDay(useGMTzone),
- wd1Index = dayOrder[wd1] || -1,
- wd2Index = dayOrder[wd2] || -1,
- result = false;
-
- if (wd2Index < 0) {
- result = (todaysDay == wd1Index);
- } else {
- if (wd1Index <= wd2Index) {
- result = valueInRange(wd1Index, todaysDay, wd2Index);
- } else {
- result = valueInRange(wd1Index, todaysDay, 6) || valueInRange(0, todaysDay, wd2Index);
- }
- }
- return result;
- }
-
- function getTodaysDay (gmt) {
- return (gmt ? (new Date()).getUTCDay() : (new Date()).getDay());
- }
-
- // start <= value <= finish
- function valueInRange (start, value, finish) {
- return (start <= value) && (value <= finish);
- }
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