Leap year date input from user crashes application and breaks subsequent attempts to load

[Eugene Teu]

I am able to input a leap year date into adding of tasks.

Specifically, add task tn/test task 1 td/29/02/2019 .
look at task 7 in the screenshot.
Also i do not have a command successful message being shown to the user

Next step: I exit the application.
e.g exit

Next step: i run the jar using
e.g java -jar

I will get a runtime error. the application breaks and cannot restart again.

After this erroneous input by the user, he will be unable to start the application again. Have to manually delete the data and start over