Millis() timer is it running even in sleep mode?

[satishbhandare]

Hi
I am using BLE_Peripherial with a nrf51822 module. Since both rtc0 and rtc1 are used by softdevice and arduino, I wish to use the millis() function to create my own RTC. Does the millis() function retains/updates its value even during sleep modes?

Thanks in advance.