How to validate & compare hours part of sharepoint datetime control? - sharepoint

Question

I have two sharepoint datetime controls where timeOnly=true. I need to validate as required field & validate as one controls Hours value must be Greater than & Equal to other one. I want to do it in Client side.
Note: Using timeOnly="true" means need to validate Hours & minutes Only.

Answer 1

you will find several good solutions by searching Google for the phrase - sharepoint datetimecontrol validation - without using quotes

Answer 2

Created an asp.net custom validator to compare hours & minutes part of two datetime controls.
And called javascript function from ClientValidationFunction property of asp.net custom validator.
Function is here:
function ValidateHour&Minute(sender, args){
var startDateHour = document.getElementById("<%=DateTimeControlStartDate.Controls[1].ClientID %>").value;// gets value from hours dropdown list for 1st datetime control
var startDateMinute = document.getElementById("<%=DateTimeControlStartDate.Controls[2].ClientID %>").value;// gets value from minutes dropdown list for 1st datetime control
var timeStart = new Date();
var timeEnd = new Date();
var strStartHour;
var hourType;
hourType = startDateHour.split(' ');
if (hourType[1] == "AM") {
startDateHour=startDateHour.split(' ');
strStartHour = startDateHour[0];
}
else {
startDateHour=startDateHour.split(' ');
strStartHour = startDateHour[0];
strStartHour = parseInt(strStartHour) + 12;
}
timeStart.setHours(strStartHour, startDateMinute, 0, 0);
var strEndHour;
var endDateHour = document.getElementById("<%=DateTimeControlEndDate.Controls[1].ClientID %>").value;// gets value from hours dropdown list for 2nd datetime control
var endDateMinute = document.getElementById("<%=DateTimeControlEndDate.Controls[2].ClientID %>").value;// gets value from minutes dropdown list for 2nd datetime control
hourType = endDateHour.split(' ');
if (hourType[1] == "AM") {
endDateHour=endDateHour.split(' ');
strEndHour = endDateHour[0];
}
else {
endDateHour= endDateHour.split(' ');
strEndHour = endDateHour[0];
strEndHour = parseInt(strEndHour) + 12;
}
timeEnd.setHours(strEndHour, endDateMinute, 0, 0);
if (timeStart < timeEnd) {
args.IsValid = true;
}
else {
args.IsValid = false;
}
}