LG M4225C Owner's Manual page 76

Controlling the Multiple Product
RS-232C
Transmission / Receiving Protocol
35. Time (Command : f a)
Set the current time.
Transmission
[Data1]
0 : Monday
1 : Tuesday
2 : Wednesday
3 : Thursday
4 : Friday
5 : Saturday
6 : Sunday
[Data2]
0H to 17H (Hours)
[Data3]
00H to 3BH (Minutes)
Acknowledgement
*When reading data, FFH is inputted for [Data1], [Data2] and [Data3].
In other cases, all are treated as NG.
A21