import { GMT, Weekday } from './index';
/**
 * 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}
 */
export default function weekdayRange(wd1: Weekday, wd2?: Weekday | GMT, gmt?: GMT): boolean;