Resolve "ValueError: day is out of range for month"

Ghost User
2020-03-11T20:27:25+01:00

Closes #1025

#### Previous behaviour
Steps to reproduce:

1. On leap years the function to get the mentor year would crash because the 29th of Feb does not exist in most years

#### New behaviour
Steps to validate that it works:

1. The if-statement checks for leap year and replaces it with 28th Feb in that case