Saman Saadi
Welcome to my personal blog
There is an independent database of different zones named tz database. Basically they named each zone start with the continent or ocean name then follows slash and finally the city or region name. For example America/Montreal, America/New_York, Asia/Tehran, Europe/London.
International Direct Dialing
If you want to call an international number, first you need to dial exit code or more formally international direct dialing (IDD) of origin country. In most European and all Middle East countries it's 00. Suppose that you want call a Canadian number from Iran, a country in the Middle East. The exit code in Iran is 00 and the country calling code for Canada is 1, so you need to dial 001 and then the Canadian number.
