Yes, my answer was on the same presumption only.
When was your Holiday for Ramzan? Saturday or Monday? It should be on Saturday. Was that pre announced? You are expected to exhibit the holidays of any year in the month of December itself. Now, if the employee without knowing that Saturday being a holiday, had applied a leave (sick leave) you can reject it saying that the day is not a working day and an employee is not supposed to take a leave on a holiday. And when she applies for a leave on Monday, how does Sunday become a sandwich leave? No.
You may see the things in a practical way. The HR is not a detective and fault finding mechanism but should be sympathetic towards the employees. If you had exhibited the holiday list well in advance, the employee would not have applied for leave on Saturday. It is upto the management whether compensatory holiday should be allowed or not and I will not grant any compensatory holiday if any employee was on leave on a day which was declared as a holiday. Now, if the employee was on leave on Saturday and he was granted compensatory holiday on Monday, then also the sandwich policy will not apply there because Monday is not a leave but you had given him a holiday.
Coming to the same question, was Saturday a working day for the organisation? If yes, you cannot mark a leave on that day. As such, if he takes a leave on Monday, the Sunday will be weekly off and cannot be marked as leave.