Though even if you consider any possible harmfull effects like thyroid nodules formation correlation [1] (people somehow only think about ionizing radiation, but there much more that happens in a cell that can be possibly disrupted without xray level stuff to damage dna or heat: there are ion channels and what have you), the Bluetooth on gshock — if set up — will work only for a few seconds twice a day. Basically nothing even if you sleep directly on it all night long

[1] https://www.nature.com/articles/s41598-024-63653-0