DatePicker: dateStyleClasses shifts to wrong date

Describe the defect When added metadata with some styles, the styles is applied to wrong date: shifts +/- one day.

Environment:

• PF Version: 10.0
• Time zone in browser is UTC+06:00

To Reproduce Steps to reproduce the behavior:

1. Set time zone on you PC to UTC+06:00
2. After 18:00 styles is shifts on next day

Solution Function toISODateString() in datepicker.js now is:

toISODateString: function (b) {
  return b.toISOString().substring(0, 10)
}

must be:

toISODateString: function (b) {
  return new Date(b.getTime() - (b.getTimezoneOffset() * 60000)).toISOString().substring(0, 10)
}

[melloware]

If someone needs this MonkeyPatch now just apply this to your application JS.

if (PrimeFaces.widget.DatePicker) {
    $.prime.datePicker.prototype.toISODateString: function(date) {
        return new Date(date.getTime() - (date.getTimezoneOffset() * 60000)).toISOString().substring(0, 10);
    }
}

[christophs78]

Propably not covered by integration tests. toISODateString is currently only called from renderDateCellContent during evaluation of this.options.dateStyleClasses. So we at least should not break other functionally. And dateStyleClasses is only populated via dateMetadata introduced with PF 10. (Think we have no integration tests for dateMetadata.)