I don't understand this code...it means, that if current code is nil, it is delete and otherwise kept?

Whole this work-flow looks quite unintuitive for me. Separate it to own methods looks fine for me, but then mixing various level of details looks wrong. For me better work-flow could be
```
updated_params = {}
updated_params.merge! update_timezone
updated_params.merge! update_utc_status
updated_params.merge! update_date_time
```
and it is up to given method if it return empty hash if nothing needed to change or raise exception or set some useful data.