Thread: Do while loop fails when more conditions are added

I'm trying to write a piece of code that calculates the difference in days between two manually input dates.

The part of my code that's causing problems is:

xxx

When running the code and prompted to enter the date, if I input for example 31/12/2014, it'll be rejected and send me back to the beginning of the loop. Any date with 31 days involving months 1, 3, 5, 7, 8, 10 or 12 causes this problem. All other valid dates however work perfectly fine (e.g. 30/4/2014).

Something possibly worth mentioning is that, when I take out all other conditions from the loop, i.e.

xxx

it works fine (31/12/2014 is accepted), but of course I need all of the other conditions in there too.

Any ideas?

Thanks