Dear colleagues, I ask for your help. There is a task to make the program for the account of working hours. The program should work without using the Internet.
The logic is very simple. The user selects the beginning of the working day, after that - indicates the end of the working day, and the date for which the data is entered.
If there is data for this period, the program offers the option of changing the data; if there is no data, the program adds the data to the storage.
BUT! My question is how best to store data, given that the months are changing, and we need to somehow automate this process + lay the option of obtaining data for a particular month. Head boiling, no ideas 