I have a wall calendar (source forgotten) that, as is typical for Jewish calendars, marks the parshiyot for each Shabbat. Next week, instead of giving the name of the parsha (Ki Tavo) it says "Chai Elul". Yes ok, I thought, next Shabbat is the 18th of Elul, but so what? I asked Google what this day is about and learned that this date is important in Chassidism as the birthday of both the Baal Shem Tov and the Alter Rebbe.
This calendar marks other special days without affecting the parsha "slot", so this wasn't the only place they could have noted it. That they replaced "Ki Tavo" with "Chai Elul" made me wonder if there's something special about the torah reading on that day in Chassidic communities. I didn't find anything in my search about special observances for the day, either as part of the torah service or more generally.
What do Chassidic communities do to mark this day? Does it affect the torah service?