Setting Arduino Time & Date

Dear all,

Suppose assume that i am not using RTC. And using Arduino time and date lib for programming.COde will work fine with untill and unless Ardunio On. Once it get shutdown.Arduino will start from time we set for. How record the last arduino time and whenever it start it should take actual time. example like in RTC itself. Is it possible to do without RTC.

or any other way of writing time in to Arduino time library.

Moderator edit: Shouty title toned-down. AWOL

Any data that is to be persisted across power outages needs to be stored in EEPROM. However, caution needs to be exercised, since EEPROM has a limited number of write cycles (large, but limited).

Time that passes while the Arduino is powered down can NOT be accounted for.

Get an RTC. They are cheap.