I know of a couple of vessels, one in particular that does an All Ships broadcast on their MF/HF DSC for a daily test. This has been going on for over a year at least. So every vessel that has GMDSS within a thousand miles has to silence their test. They have become a nuisance for hundreds of people on a regular basis.
STCW B-VIII, 17.2 "the distress and safety radio equipment by means of a test at least once each day but [B][U]without radiating any signal[/U][/B]l."
As far as STCW B-VIII, 17.1 (for weekly test transmissions) you can refer to ITU-R M.541-8, Annex 3 part 5; "Testing on the exclusive DSC and safety calling frequency 2187.5 KHz should be avoided as far as possible by using other methods.
“Test calls should be transmitted by the ship and acknowledged by the called coast station…”
The easiest way I’ve found is to do a DSC to a specific vessel, letting them know ahead of time, so you can verify functionality of the system. The other vessel can do the same in return and both ships will have verified their system for a weekly test.
Anyway if every boat did an All Ships call for a daily or even weekly test our equipment would probably explode along with our heads.
A daily test can be conducted by the Self Check or Self Test or Self Diagnostic function on the system.