If there is anywhere in Herzegovina that you can reach day or night it is most certainly Medugorje.
There are half a dozen
daily buses to Medugorje from Mostar, starting at 06.30 in the morning and running until at least 19.00. Dubrovnik, Split, Makarska and Zagreb all have regular buses to Medugorje as well.
From Mostar’s main bus station busses go every day to
Medugorje on hourly basis. The one-way ticket (depending on
a bus company) costs between 4 and 6 KM. There is also a
daily city bus (no. 48) from 3 KM.
Sarajevo- Medugorje: 14.30; 16.45. A one way ticket
costs 22 KM
Ploce - Medugorje: every day at 13.10 and 19.30. A
one way ticket costs approximately 35 Croatian kuna