Add test for firstDateOfMonth
Add test for lastDateOfMonth
Add test for withWeekDay
Reformat tests
Add test for getOnlyDate
Update Idea project file
Remove useless getTimezone function
Remove duplicate implementation getDayOfYear which does same as getDayInYear
Remove getWeekOfYear from DateFormat since it is duplicate
Remove useless isLeapYear function
Remove getSuffix from DateTime since it is locale sensitive
Add test for isWeekend
Add test for toString and fix it to return local times