Understanding Sandwich Leave Policy
Normally, when both ends, i.e., Saturday and Tuesday, are on leave, the sandwiching of leaves would take place. This also depends upon the law in force. If it is a factory, then the Factories Act will be applicable. If the leave taken is earned leave, then you cannot consider the intervening holidays, i.e., Sunday and Monday, as leave days. This means sandwiching is not permitted under the Factories Act.
Shops Act and State Provisions
The Shops Act is a state Act, so you have to refer to its provisions. However, one thing is common: if the leaves are 'earned' by an employee by working for a certain number of days in the preceding year, like one day for every 20 days worked, the leave should not be sandwiched. At the same time, if the leave is not as per any law but is over and above what is mandated by any law, then the employer can do sandwiching because that leave is an employee benefit offered by the employer and not as per the law.
In short, sandwiching is permissible only if both ends are leaves. In this example, if the employee is on leave on Saturday, and Monday is a holiday, and he comes to the office on Tuesday, then there cannot be any sandwiching.