Exp 100% 50% 0%

Well, here is another thing i discovered since i play Silkroad-R
under the HP/MP bar, you obviously observed that there is another bar, a yellow bar.
8hours a day is 100% - yellow
4hours a day is 50%   - red (after 100% is over)
rest of the day is 0%   - grey (after 50% is over)
when you are on 0% you are not able to buy HP/MP nothing els (like potion), you are not able to  level up. That means you only have 12 hours a day to grind. 8hours 100%, 4hours 100%, then you have to rest a bit:)

there is how it looks like :