Insert cell formatting on change of value in Column A

Column A has dates - sorted oldest to newest
Column B:M has other data



Each date in column A has a varying number of entries.
On the last entry for each date I want to insert a thick bottom border in the that row from Column A to I.

Column A has a varying number of rows. Sometimes it is 1000, sometimes it is only 50.

I have attached a sample workbook for reference.

Any assistance appreciated.

Thanks JD.