LED string timer

Hi,
Is it possible to control a DC LED string so the it would light up at 7 PM (for example) and will turn off at 10 PM?
I have this type of string (3 AA batteries):

Is it possible to control a DC LED string so the it would light up at 7 PM (for example) and will turn off at 10 PM?

Yes

Could you elaborate, please? Or attach a link to a project?
Thanks

The simplest way would be to use a Real Time Clock to maintain accurate timing and to switch a relay on/off at the appropriate times.

A (mechanical) timer switch would work perfectly for a job like this. Just plug in the LED string's power supply, set the clock, done.