How to modify Java script based on time zone？

[shiz]

I have the following Java scientist code:

function onLoad() {

    //Type appropriate comment here, and begin script below

    if (g_form.isNewRecord()) {

        var today = new Date();

        var day = today.getDay();

        // Calculate the Monday of the current week

        var monday = new Date(today.setDate(today.getDate() - (day === 0 ? 6 : day - 1)));

        g_form.setValue('u_week_starts_on', monday.toISOString().split('T')[0]);

        // set field is readonly

        g_form.setReadOnly('u_week_starts_on', false);  

        g_form.setReadOnly('u_assigned_to', false);  

    }else{

        // set field is readonly

        g_form.setReadOnly('u_week_starts_on', true);  

        g_form.setReadOnly('u_assigned_to', true);  

    }

Now I have discovered this issue, when I set the time zone to the US location in Tokyo,
Due to the time difference, the value of 'Monday' obtained in the code is not the Monday of the current week, but the Sunday of the previous week.

I want to achieve that no matter where the time zone is switched globally, the value of 'Monday' obtained in the code will always be Monday. How can I modify the JavaScript in this way?

[shiz]

Another additional issue is that I want to check the Monday settings in the business role, but using the following code seems to yield an error. Do modifications also need to be made in the business role? How can you help me? Thank you so much.

(function executeRule(current, previous /*null when async*/) {

    // Add your code here

    var weekStartOn = new GlideDateTime(current.u_week_starts_on);

    var day = weekStartOn.getDayOfWeekLocalTime();

    if (day != '1') {

        //Check if the week start on is Monday

        //gs.addErrorMessage('Week start day has been set to Monday in the time sheet policy Default time sheet policy. You must choose a date that is a Monday.'); // Change the message as per your requirement

        gs.addErrorMessage(gs.getMessage('check_week_start_on'));

        current.setAbortAction(true);

    }

[Omkar Kumbhar]

@shiz remove the quotes for day! = 1

function executeRule(current, previous /*null when async*/) {

var weekStartOn = new GlideDateTime(current.u_week_starts_on);
var day = weekStartOn.getDayOfWeekLocalTime();

// Check if the selected day is NOT Monday (Monday = 1)
if (day != 1) {
gs.addErrorMessage(gs.getMessage('check_week_start_on'));
current.setAbortAction(true);
}
}

[VijayKumarDodde]

function onLoad() {
if (g_form.isNewRecord()) {
var nowDate = new Date();

var utcDay = now.getUTCDay();

// Calculate the UTC date of Monday of the current week
var utcMonday = new Date(Date.UTC(
now.getUTCFullYear(),
now.getUTCMonth(),
now.getUTCDate() - (utcDay === 0 ? 6 : utcDay - 1)
));

g_form.setValue('u_week_starts_on', utcMonday.toISOString().split('T')[0]);

// Make fields editable
g_form.setReadOnly('u_week_starts_on', false);
g_form.setReadOnly('u_assigned_to', false);
} else {
// Make fields read-only for existing records
g_form.setReadOnly('u_week_starts_on', true);
g_form.setReadOnly('u_assigned_to', true);
}
}

Please mark it as helpful.

[shiz]

Another additional issue is that I want to check the Monday settings in the business role, but using the following code seems to yield an error. Do modifications also need to be made in the business role? How can you help me? Thank you so much.

(function executeRule(current, previous /*null when async*/) {

    // Add your code here

    var weekStartOn = new GlideDateTime(current.u_week_starts_on);

    var day = weekStartOn.getDayOfWeekLocalTime();

    if (day != '1') {

        //Check if the week start on is Monday

        //gs.addErrorMessage('Week start day has been set to Monday in the time sheet policy Default time sheet policy. You must choose a date that is a Monday.'); // Change the message as per your requirement

        gs.addErrorMessage(gs.getMessage('check_week_start_on'));

        current.setAbortAction(true);

    }

[Ankur Bawiskar]

@shiz 

what's your business requirement?

what are you trying to achieve?