function getTimeZoneOffset(timeZoneId) {
    var timezoneOffsets = {
        "US/Pacific": -7 * 60 * 60 * 1000,
        "US/Mountain": -6 * 60 * 60 * 1000,
        "US/Central": -5 * 60 * 60 * 1000,
        "US/Eastern": -4 * 60 * 60 * 1000,
        "Europe/London": 0 * 60 * 60 * 1000,
        "Europe/Berlin": 1 * 60 * 60 * 1000,
        "Europe/Paris": 1 * 60 * 60 * 1000,
        "Europe/Madrid": 1 * 60 * 60 * 1000,
        "Europe/Rome": 1 * 60 * 60 * 1000,
        "Europe/Warsaw": 1 * 60 * 60 * 1000,
        "Europe/Moscow": 3 * 60 * 60 * 1000,
        "UTC": 0 * 60 * 60 * 1000,
        "GMT": 0 * 60 * 60 * 1000,
    };

    return timezoneOffsets[timeZoneId] || 0;
}

function normalizeIncompleteDatetime(value, timeZoneId) {
    logger("Original value: " + value);

    // Split the date and time parts
    var parts = value.split('T');
    var datePart = parts[0].split('-');

    // Default year, month, and day
    var year = datePart[0] ? parseInt(datePart[0], 10) : 0;
    var month = datePart[1] && datePart[1].trim() !== '' ? parseInt(datePart[1], 10) - 1 : 0;  // Default to January (month = 0)
    var day = datePart[2] && datePart[2].trim() !== '' ? parseInt(datePart[2], 10) : 1;        // Default to 1st of the month

    // Split the time part and pad missing parts with defaults
    var timePart = parts.length > 1 ? parts[1].split(':') : [];
    var hour = timePart[0] && timePart[0].trim() !== '' ? parseInt(timePart[0], 10) : 0;
    var minute = timePart[1] && timePart[1].trim() !== '' ? parseInt(timePart[1], 10) : 0;
    var second = timePart.length > 2 && timePart[2].trim() !== '' ? parseInt(timePart[2], 10) : 0;

    // Create the Date object directly in the local timezone
    var normalizedDatetime = new Date(year, month, day, hour, minute, second);

    // Check if the date is valid
    if (isNaN(normalizedDatetime.getTime())) {
        logger("Error: Invalid Date created from input value.");
        customErrorMessage('The datetime "' + value + '" could not be interpreted as a valid date.');
        return null;
    }

    // Adjust the datetime according to the timezone offset
    var timezoneOffset = getTimeZoneOffset(timeZoneId);
    normalizedDatetime = new Date(normalizedDatetime.getTime() - timezoneOffset);  // Corrected: Subtracting the offset to convert from MT to UTC
    logger("Date object adjusted for " + timeZoneId + ": " + normalizedDatetime);

    return normalizedDatetime;
}

function isNotInFuture(datetimeValue, timeZoneId) {
    logger("Starting isNotInFuture check...");

    // Normalize the incomplete datetime value directly in the timezone
    var normalizedDatetime = normalizeIncompleteDatetime(datetimeValue, timeZoneId);
    if (!normalizedDatetime) {
        // Return false if we couldn't create a valid date
        return false;
    }

    logger("Normalized datetime for comparison: " + normalizedDatetime);

    // Get the current time adjusted to the local timezone
    var now = new Date();
    logger("Current local time: " + now);

    // Compare the datetime
    if (normalizedDatetime.getTime() >= now.getTime()) {
        var errorMessage = 'The datetime "' + datetimeValue + '" is in the future or exactly at the current time, which is not allowed.';
        logger("Error: " + errorMessage);
        customErrorMessage(errorMessage);
        return false;
    }

    logger("Datetime is not in the future.");
    return true;
}

// Extract the timezone from formJson
var timeZoneId = formJson.form.subject.volunteer.site.timeZoneId;
logger("TimeZone ID: " + timeZoneId);

// Run the check against the provided item value
logger("Item value: " + itemJson.item.value);
var isValid = isNotInFuture(itemJson.item.value, timeZoneId);
logger("Validation result: " + isValid);
return isValid;