The Berry guy in D/P/Pt

Hey guys, I'm trying to get some berries so I'm using the berry guy on route 208, anyways, since I need a lot, I tried to change the date and time to make the event appear again (it's once a day), but it doesn't work.
Is there any specific thing I need to do?
I even changed the date by a couple months and the guy still wouldn't give me more berries.

Probably has a 24 hour delay from when you change the date. Similar thing occurs with Pal Park.

Probably has a 24 hour delay from when you change the date. Similar thing occurs with Pal Park.

Dam. I heard it's possible to do it multiple times by doing something, just dont know what. D::

Change the clock to 23:59, start the game, and wait one minute.

Change the clock to 23:59, start the game, and wait one minute.

That must have been it, it worked. :o
Jesus, you did your research like crazy.