03/09/2021
The COMELEC may set an earlier deadline for substitution due to withdrawal.
Unlike death or disqualification, withdrawal is voluntary. Generally, a candidate has sufficient time to ponder on his candidacy and to withdraw while the printing has not yet started. If a candidate withdraws after the printing, the name of the substitute candidate can no longer be accommodated in the ballot and a vote for the substitute will just be wasted.
Federico vs. COMELEC, G.R. No. 199612, January 22, 2013