I am wanting to create a data bar(progress bar), but will the bar only work when there is a number in the cell, or will it be able to make to the bar move up or down when a date is entered in the cell

for example

i will have 8 columns e.g. a-h, and say when 4 of the columns have a date in it it will make the data bar(progress bar) say 50% and then obviously go up as more of the columns have a date in it, but i want it to do this when there is a date and not a number

Hopefully this makes sense, and is possible

Any help will be great