Generally reserved days are scheduled on the next day of the actual match day in every tournaments.
From IPL's match playing conditions:
50. IPL 2014 PLAYOFF MATCHES
5. A reserve day is available for three of the four playoff matches, as follows:
a. Qualifier 1 – reserve day: Wednesday 28 May at Eden Gardens, Kolkata starting at 4pm
b. Eliminator – reserve day: Thursday 29 May at CCI, Mumbai starting at 8pm
c. Qualifier 2 – no reserve day
d. Final – reserve day: Monday 2 June at M. Chinnaswamy stadium, Bengaluru starting at 8pm
Since there is no reserve day for Qualifier 2 the winner will be decided as per below conditions: (emphasis mine)
For the Qualifier 2 playoff match (no reserve day), in the event that it is not possible to schedule a 5 over match to complete by the end of the extra time that evening/night, the teams will, if conditions permit, play a Super Over to determine the winner of the Qualifier 2. The pitch and ground must be ready for play so that the Super Over can start at the latest by 1.10am on Saturday 31 May.
If it is not possible to start the Super Over as described in the above paragraph or to then complete the Super Over without interruption, the team that finished highest in the league table after the 56 matches of the regular season shall be declared the winner of the relevant playoff match.