Light-Weight Javascript Duration Parser

Duration-Parser.js

parseIso8601Duration(iso8601Duration) {
    const iso8601DurationRegex = /(-)?P(?:([.,\d]+)Y)?(?:([.,\d]+)M)?(?:([.,\d]+)W)?(?:([.,\d]+)D)?T{0,1}(?:([.,\d]+)H)?(?:([.,\d]+)M)?(?:([.,\d]+)S)?/;
    const matches = iso8601Duration.match(iso8601DurationRegex);
    return {
        sign: matches[1] === undefined ? '+' : '-',
        years: matches[2] === undefined ? 0 : Number(matches[2]),
        months: matches[3] === undefined ? 0 : Number(matches[3]),
        weeks: matches[4] === undefined ? 0 : Number(matches[4]),
        days: matches[5] === undefined ? 0 : Number(matches[5]),
        hours: matches[6] === undefined ? 0 : Number(matches[6]),
        minutes: matches[7] === undefined ? 0 : Number(matches[7]),
        seconds: matches[8] === undefined ? 0 : Number(matches[8])
    }
}

iso8601Duration2Seconds(iso8601Duration) {
    const d = parseIso8601Duration(iso8601Duration)
    const f = d.sign === '-'? -1:1
    const ds = 24*60*60
    return f * (d.years*365*ds + d.months*30*ds + d.weeks*7*ds +
        d.days*ds + d.hours*60*60 + d.minutes*60 + d.seconds )
}