sets the date format
| format | string | date format |
myCalendar.setDateFormat("%d/%m/%y");
default date format is "%Y-%m-%d"
| %d | day as a number with leading zero, 01..31 |
| %j | day as a number, 1..31 |
| %D | short name of the day, Su Mo Tu... |
| %l | full name of the day, Sunday Monday Tuesday... |
| %m | month as a number with leading zero, 01..12 |
| %n | month as a number, 1..12 |
| %M | short name of the month, Jan Feb Mar... |
| %F | full name of the month, January February March... |
| %y | year as a number, 2 digits |
| %Y | year as a number, 4 digits |
| %h | hours 12-format with leading zero, 01..12) |
| %g | hours 12-format, 1..12) |
| %H | hours 24-format with leading zero, 01..24 |
| %G | hours 24-format, 1..24 |
| %i | minutes with leading zero, 01..59 |
| %s | seconds with leading zero, 01..59 |
| %a | am or pm |
| %A | AM or PM |
| %% | escape for % |