ESP32 Arduino Deep Sleep Time

[topalpanda]

Hi there,
On my project i am using deep sleep feature of esp32. My device can awaken by timer and internal button too. When i go to sleep with adjusted time(timer deep sleep, constant 12h) Someone can push to button and awaken my device. If this scenario occurs my timer wake up time will shift. But i want my device wake up same time at every day. For instance Every day 10:00 and 22:00. So i must calculate the time has passed while my device sleeping to update my sleep interval.

How can i do that?