It can convert any date from 62 Before Hejrat to 3177 After Hejrat.
To convert, select the date you want to convert. The converted date will be shown after you select day of the month.
There are two text boxes under each calendar. The first box shows the date you selected to convert and the second box shows the converted date. The first text box also shows the difference in days between currently selected date and the last selected date on the same calendar.
There is also a button under each calendar to show the converted date on the other calendar.
Acknowledgment
Conversion is based on a research paper by Polish astronomer Kazimierz M. Borkowski Ph.D.
It is based on calculating the exact time of vernal equinox in Tehran and is, therefore, more accurate than the 2820-year model.
