Dynamic Dropdown + Automated Counter + Time Difference.
I would need help on the following :
Dynamic Dropdown + Automated Counter + Time Difference.

I have attached the file in which I have mentioned the requirements.

1. Dynamic Dropdown :

I have a column mentioning vertical, based on the choice selected in this dropdown in the adjoiing column should display only those values in that drop-down.


2. Automated Counter :

There would be several activities done in a day for a single date, the date is mentioned the column only once so the counter needs to keep a track of the row numbers before it encounters the new date.


3. Time Difference :

The time should work for a 24 hour clock...and not only for 8 hours...(regular shift) The Start time cannot always be less than the End time so if goes in the next day then there arises an error.