Add date to next available cell, ignore existing date entries

I searched the forum posts using "date" as my search criteria and did not see an answer for what I would like to accomplish. I need to specify just the column where the date will be placed/exist which is started at B8. The logic is fairly straight forward as it needs to check to see if there is already a date there. If the cell is occupied nothing happens. If the cell is empty then it triggers using = NOW() to insert date. I would like this to happen when the spreadsheet opens. There will be only one workbook so nothing special to deal with there.

Summarized the program will parse the B column for existing dates, when it finds the next available cell it will add the date. As stated it will trigger on open of the spreadsheet. I look forward to seeing the solution.

Regards,

Mel

Thanks JasperD!