function _ctParseLocalDate(s) {
        s = (s || '').trim();
        if (!s) return new Date();
        // Accept ISO-ish like 2026-05-14 09:00 or 2026-05-14T09:00
        var m = s.match(/^(\d{4})-(\d{2})-(\d{2})[ T](\d{1,2}):(\d{2})(?::(\d{2}))?$/);
        if (m) {
            return new Date(Date.UTC(+m[1], +m[2]-1, +m[3], +m[4], +m[5], +(m[6]||0)));
        }
        var m2 = s.match(/^(\d{4})-(\d{2})-(\d{2})$/);
        if (m2) {
            return new Date(Date.UTC(+m2[1], +m2[2]-1, +m2[3]));
        }
        var d = new Date(s);
        if (!isNaN(d.getTime())) return d;
        return null;
    }

    function _ctZoneOffsetMinutes(date, tz) {
        try {
            var dtf = new Intl.DateTimeFormat('en-US', {
                timeZone: tz, year:'numeric', month:'2-digit', day:'2-digit',
                hour:'2-digit', minute:'2-digit', second:'2-digit', hour12:false
            });
            var parts = {};
            dtf.formatToParts(date).forEach(function(p){ if (p.type !== 'literal') parts[p.type] = p.value; });
            var asUTC = Date.UTC(+parts.year, +parts.month-1, +parts.day, +parts.hour === 24 ? 0 : +parts.hour, +parts.minute, +parts.second);
            return (asUTC - date.getTime()) / 60000;
        } catch (e) { return 0; }
    }

    function convert(input) {
        var fromTz = (document.getElementById('tz-from') || {}).value;
        var toTz = (document.getElementById('tz-to') || {}).value;
        if (!fromTz || !toTz) return '';

        var localInFrom = _ctParseLocalDate(input);
        if (!localInFrom) return 'Could not parse the date / time. Try something like 2026-05-14 09:00';

        // localInFrom is currently parsed as a UTC instant with the wall-clock components.
        // Subtract the source zone offset to find the real UTC instant.
        var fromOffset = _ctZoneOffsetMinutes(localInFrom, fromTz);
        var trueUtc = new Date(localInFrom.getTime() - fromOffset * 60000);

        var optsLong = { timeZone: toTz, dateStyle: 'full', timeStyle: 'long' };
        var optsShort = { timeZone: toTz, year:'numeric', month:'2-digit', day:'2-digit', hour:'2-digit', minute:'2-digit', hour12:false };
        var pretty = new Intl.DateTimeFormat(undefined, optsLong).format(trueUtc);
        var iso = new Intl.DateTimeFormat('sv-SE', optsShort).format(trueUtc);
        var utcStr = trueUtc.toISOString().replace('T', ' ').replace('.000Z', ' UTC');

        return pretty + '\n' + iso + '  (' + toTz + ')' + '\n\nUTC instant: ' + utcStr;
    }

    function _ctPopulateZones() {
        var zones = [];
        try {
            if (Intl.supportedValuesOf) zones = Intl.supportedValuesOf('timeZone');
        } catch (e) {}
        if (!zones.length) zones = ['UTC','America/Los_Angeles','America/Denver','America/Chicago','America/New_York','Europe/London','Europe/Paris','Europe/Berlin','Asia/Dubai','Asia/Singapore','Asia/Tokyo','Australia/Sydney','Pacific/Auckland'];

        var fromSel = document.getElementById('tz-from');
        var toSel = document.getElementById('tz-to');
        if (!fromSel || !toSel) return;
        var local = Intl.DateTimeFormat().resolvedOptions().timeZone || 'UTC';
        zones.forEach(function(z) {
            fromSel.appendChild(new Option(z, z));
            toSel.appendChild(new Option(z, z));
        });
        fromSel.value = local;
        toSel.value = (local === 'UTC' ? 'America/New_York' : 'UTC');
    }

    $(function(){
        _ctPopulateZones();
        $('#tz-from, #tz-to').on('change', function(){ $('#box1').trigger('keyup'); });
        $('#tz-swap').on('click', function(){
            var f = $('#tz-from').val(); var t = $('#tz-to').val();
            $('#tz-from').val(t); $('#tz-to').val(f);
            $('#box1').trigger('keyup');
        });
        // Default to current local time if input empty
        if (!$('#box1').val()) {
            var now = new Date();
            var pad = function(n){ return n < 10 ? '0' + n : '' + n; };
            $('#box1').val(now.getFullYear() + '-' + pad(now.getMonth()+1) + '-' + pad(now.getDate()) + ' ' + pad(now.getHours()) + ':' + pad(now.getMinutes())).trigger('keyup');
        }
    });







var _loadedScripts = {};
function loadScriptPromise(url) {
    if (_loadedScripts[url]) return _loadedScripts[url];
    _loadedScripts[url] = new Promise(function (resolve, reject) {
        var s = document.createElement('script');
        s.src = url;
        s.onload = resolve;
        s.onerror = reject;
        document.head.appendChild(s);
    });
    return _loadedScripts[url];
}

function replaceAll(find, replace, str) {
    return str.replace(new RegExp(find, 'g'), replace);
}

function beautify(str) {


    var result = '';

    var length = str.length;

    var i = 0;

    var braceCountLeft = 0;
    var braceCountRight = 0;

    var withinQuotes = false;

    while (i < length) {

        var c = str[i];

        if (c == '"' && (i == 0 || c[i - 1] != '\\')) {
            // non-escaped quotes
            withinQuotes = !withinQuotes;
        }

        if (!withinQuotes && (c == '}' || c == '{' || c == ',')) {

            console.log('Start####' + result);

            // look back and remove carriage returns and whitespace that are already there

            var resultIndex = result.length - 1;
            while (resultIndex >= 0 && (result[resultIndex] == ' ' || result[resultIndex] == '\r' || result[resultIndex] == '\n' || result[resultIndex] == '\t')) {

                resultIndex = resultIndex - 1;
                result = result.substr(0, resultIndex + 1);

                console.log('char ' + result[resultIndex] + '-----' + result + 'zzz ' + result.length + ' ' + resultIndex);

            }


            if (c == '{') {
                braceCountLeft++;
                result += c + '\r' + GetTabs(braceCountLeft - braceCountRight);
            } else if (c == '}') {
                braceCountRight++;
                // precede with carriage return
                result += '\r' + GetTabs(braceCountLeft - braceCountRight) + c;
            } else if (c == ',') {
                result += c + '\r' + GetTabs(braceCountLeft - braceCountRight);
            }

            var nextChar = '';

            // advance through whitespace and remove carriage returns that are already there
            while (i < length && (str[i + 1] == ' ' || str[i + 1] == '\r' || str[i + 1] == '\n' || str[i + 1] == '\t')) {
                i++;
            }

        } else {

            result += str[i];

        }


        i++;

    }

    return result;

}

function GetTabs(count) {

    var result = '';

    for (var i = 0; i < count; i++) {
        result += '    ';
    }

    return result;

}