Welcome to the Ranch.
That's a lot of code to wade through!
It looks like your program is expecting a date in the format "yyyy-MM-dd" (4 digits year, a '-' character, 2 digits month, a '-' character and 2 digits day) because that's what you specified when making the SimpleDateFormat object.
A date like "8/4/1955" does not look like the format "yyyy-MM-dd". It should have been "1955-04-08". Or
you should have specified a different format when creating the SimpleDateFormat object, for example "dd/MM/yyyy". (Is it month/day or day/month?).