Static Check Boxes With Time Stamp

I have a spreadsheet in which a check box fills the corresponding cell with the value "TRUE" if checked and "False" if unchecked. I use this check box for several functions (e.g. assigning a unique ID number). One of the functions I would like to make is a time and date stamp in another column when a user checks a box.

I have perused some of the past topics on this subject and there are a few hiccups in the other fixes.

1. I can't simply set the iterations to one because this sheet also is used to calculate expenditures, fund balances, etc. I need the calculations to be ongoing.

2. I currently have a check box macro that placed a check box on a thousand rows. It may require more rows later on. I need a solution that sets up a time stamp for all of these rows, not just a macro for one row at a time.

3. I need the time stamp to be static. I need to know when entries were made. I cannot use track changes, because we will be using this data to measure the effectiveness of our process. I need to be able to add and subtract the time between the timestamps.