Count of restaurant checks for each day of a year

This should be easy, but I can't figure it out. Column A contains the numerical guest check number from a restaurant (unique to only one day. After midnight, the check numbering system resets), column B is the date of that guest check, so if there are 10 checks for 1/1/2017, there will be 10 rows, where column B will show 1/1/2017 in each of the rows. Apply the same logic to an entire year's worth of guest checks. I need to find out how many guest checks were rung up each day.

I added column C which shows the dates of the year incrementing by 1. In column D I tried to add a formula that looks at the date from column C within column A, then returns the count of that day's guest checks from column B. No idea how to accomplish this. Any help much appreciated!

Upload sample file please. When dealing with dates, it is important for us to see what exactly is stored in the range.
Ex: DateTime value but formatted as date. Text value that looks like date value. etc.

Or you can just use pivot table to summarize data, instead of using formula.

Try this in column D, assuming your data starts on row 2:

=COUNTIF(B:B,C2)