Click-Fill Current and Upcoming dates

[Pharper]

First off, I apologize for not making a better post title. My lack of knowledge about various parts of Excel made it impossible for me to state more clearly the task at hand that I am having trouble with.

This post relates to two questions.

1. Click Fill - Current Date, Day, Time
I'd like to know what code to use that will automaticaly fill a specific cell with the current date, day and time, when the cell is clicked. This may not be possible within Excel, but I am not sure.

2. Upcoming Date, Day, Time
I'd like to know how to build the correct code to generate and fill a specific cell with an upcoming date and day, based on the original date and other variables, once the other variables have been entered.

I'd like to know how to build the correct code to generate and fill a specific cell with an upcoming time (AM or PM), based on the original date and other variables, once the other variables have been entered.

Since a picture is worth a thousand words, I've attached a worksheet that should more clearly enable visualization of these questions.

While a specific solution would be nice, I'm not above reading to solve these problems. The issue is that I have no idea where to start, let alone what I should search for to read up on these questions. Any help on this is appreciate! Thanks!

[davesexcel]

Here is the first answer, the book has been saved as a macro enable workbook.