The BeagleBone and BeagleBone Black do not have a real time clock (RTC). So you need to set the date and time manually or from the network after every boot.
To set the time automatically from the network, you can use connman's built-in NTP (network time protocol) support to do this.
The nice thing about the connman approach, is that connman will load the time whenever a new network connection becomes available.
Just do this:
Using the BeagleBone >