Yes, my answer was based 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 is a holiday, had applied for leave (sick leave), you can reject it by stating that the day is not a working day, and an employee is not supposed to take leave on a holiday. And when she applies for leave on Monday, how does Sunday become a sandwich leave? No.
You may see things in a practical way. HR is not a detective or fault-finding mechanism but should be sympathetic towards the employees. If you had displayed the holiday list well in advance, the employee would not have applied for leave on Saturday. It is up to the management whether compensatory holiday should be allowed or not, and I will not grant any compensatory holiday if an employee was on leave on a day that was declared a holiday. Now, if the employee was on leave on Saturday and was granted a compensatory holiday on Monday, then also the sandwich policy will not apply there because Monday is not a leave day; instead, it was given as a holiday.
Continuing with the same question, was Saturday a working day for the organization? If yes, you cannot mark a leave on that day. Therefore, if the employee takes leave on Monday, Sunday will be the weekly off and cannot be marked as leave.