What about the following approach:

• use Date::Calc for convenient date-calculations, including leap-year-support etc.
• extract year, month, day ... from your dates (e.g. by using a regex)
• increase your date by one in a loop (using Add_Delta_DHMS)
• if the new date is equal to the end-date, end the program
• else transform the new date in your format, print it and continue your loop

HTH, Rata