Draw border when date in column A changes

Dear all,

I need a small formula to draw a border when date changes.
Things are as follows:
- on column A i have a lot of dates (01.01.2019, 02.01.2019, 03.01.2019, etc). Some of the dates are repeating (01.01.2019, 02.01.2019, 02.01.2019, 03.01.2019, etc)
- i need a formula that draws a border from column A to column C when date in column A changes.
I tried to do it with conditional formating, but no result...

A l B l C
01.01.2019 l 123 l 456
02.01.2019 l 789 l 451
02.01.2019 l 452 l 778
------------------------------------
03.01.2019 l 555 l 369
03.01.2019 l 137 l 691
------------------------------------
04.01.2019 999 777

Thank you in advance

Thank a lot KOKOSEK.
It works perfectly. Such a simple solution.