the Question Is  regarding Leave  Record ,  to calculate no of days based on start date  and End Date  and Also There is one Picklist field as a Leave Type and the picklist Values are 1) First half  2)  Second Half and 3) Full day 
 if user Select The First half With start date  and Date As same Then in no of days it should populate  0.5(no_of_Days__c is a formula Field)

 This formula Working fine for without picklist values we need to only do for FIRST HALF and SECOND HALF  Picklist Values .
  IF(End_Date__c == Start_Date__c, 1, (End_Date__c - Start_Date__c )+ 1)


 

the Question Is  regarding Leave  Record ,  to calculate no of days based on start date  and End Date  and Also There is one Picklist field as a Leave Type and the picklist Values are 1) First half  2)  Second Half and 3) Full day 
 if user Select The First half With start date  and Date As same Then in no of days it should populate  0.5(no_of_Days__c is a formula Field)

 This formula Working fine for without picklist values we need to only do for FIRST HALF and SECOND HALF  Picklist Values .
  IF(End_Date__c == Start_Date__c, 1, (End_Date__c - Start_Date__c )+ 1)