Time units of the Mean Anomaly

[Philosophaie]

M(t) = M0 + n (t - t0)

where M(t) = the Mean Anomaly at time t;
M0 = the Mean Anomaly at the Epoch time;
n = (G*(Me+Msat)/a^2)^.5 = the satellite orbit's Mean Motion;
t = the chosen prediction time; and
t0 = the Epoch time.

My question is what are the time units in (Days, Hours, etc)?

[ideasrule]

They're in whatever units would make M(t) unitless, so they depend on what units you use to calculate n. If you use SI, n should be in units of s^-1, so t should be in seconds.