Aaj kal aap aksar sunte hain Shamsi, Miladi, aur Hijri nizamoon ke baare mein. Zyaada logon ko lagta hai in tamam tareeqon ko samajhna. Dar असल, yeh tamam tareeqe duniya ke hisse mein zamaney time ke ansaar hain. Miladi tareeqa {goi ki | shabashme' | bas] saal ke din ki sankhya par mabni hai aur Shamsi tareeqa suraj ke ghiraaron ke rakhne pa