Help with Modbus time stored as high and low bytes

I have an inverter that stores dates and times in a rather frustrating way as I would like to update them from Home assistant and it looks like while I can use a read lambda to generate a suitable output writing back may be an issue.
Any help would be much appreciated.
The Value is stored with the High byte as the Hour and the Low as the minute, which I am sure I could convert to a unix time stamp or other time representation in a lambda.
But how I make that available as a modifyable time stamp that can be written back to modbus I am not sure and need a little guidance for.

Thank you and regards,