SQL 2012 :: Checking If A Date Exists In Particular Daterange

I have a table called as Events and below are its columns

ID int
EventFromDate datetime
EventToDate datetime
EventDesc nvarchar
IsHoliday bit

This is a master table where the admin would enter the Events/Holidays for the entire year.

The data would be as below:

IDEventFromdateEventTodateEventDesc isHoliday
126-01-201526-01-2015RepublicdayYes
230-01-201531-01-2015TeamOutingNo
301-05-201501-05-2015Labour day Yes

Now, suppose a employee applies leave on 26/01/2015 to 26/01/2015 then it should not insert into table and return a value "Not updated"

How to handle the scenario if a employee applies leave between the range 23/01/2015 to 27/01/2015, since 26/01/2015 is a holiday in between. how the data can still be inserted excluding 26/01/2015

Can we exclude a non-working day or a sunday.

Leavedetails table to insert leaves applied by employee is as follows

LeaveDetailID int
LeaveTypeId int
FromDate datetime
EndDate datetime
Remarks nvarchar