Regarding date validation in on change scripting

[SNOW24]

Client Script : onChange Create a new date field 'NEXT REVIEW DATE' and write code. Condition is : restrict the date field as it may allow only next 10 days from today

[Yousaf]

Hi snow,
Please try this code make changes if needed

function onChange(control, oldValue, newValue, isLoading, isTemplate) {
	if (isLoading || newValue === '') {
		return;
	}
	var today_dateStr = formatDate(new Date(),g_user_date_time_format);
	var thirty_days_from_today = new Date();
	//add 10 days to today's date.
	thirty_days_from_today.setDate(thirty_days_from_today.getDate()+10);
	var thirty_days_from_todayStr = formatDate(thirty_days_from_today,g_user_date_time_format);
	var todayNum = getDateFromFormat(today_dateStr,g_user_date_time_format);
	var thirty_daysNum = getDateFromFormat(thirty_days_from_todayStr,g_user_date_time_format);
	var selected_dateNum = getDateFromFormat(newValue,g_user_date_time_format);
	if(selected_dateNum < todayNum || selected_dateNum > thirty_daysNum) {
		g_form.showFieldMsg('expected_start','Date should be between Today and 10 days from Today','error',true);
	} else {
		g_form.hideFieldMsg('expected_start',true);
	}
}

Reference : Asif noor's article on date validation

Mark Correct and Helpful if it helps.