Connect the radio to a constant USB power source, turn the radio on and leave it on for at least 2 days on external power.
This should fully charge the clock battery that should keep the time for about 1 week or more.
Then you can set the time and forget about it.
I only set the time on my radio once and I have not had any issues.
AOR AR5000+3 & SDU, AR8000, Icom R71A, R7100, PRO2004, PRO2006, PRO43, PRO96, PRO2096, BC785D, HP1E, 396XT, 996XT, 436HP, 536HP. Probably missed some gear. Man, I gotta get rid of some of this stuff!