Returning home from his annual vacation, Mugabe told journalists that 2013 was "definitely a year of reckoning", according to a Herald online report.
"The figure 13 is bad luck for others, not us," Mugabe said in reference to his political opponents.
Zimbabwe is set for elections this year and the failure by Copac (Zimbabwe Constitution Select Committee) to wind up the constitution-making process is likely to see the country holding elections under the current supreme law.
Mugabe is on record stating that the country would head to elections with or without a new constitution.
Mugabe's party Zanu-PF and Prime Minister Morgan Tsvangirai's MDC are deadlocked over a proposed reduction of presidential powers, among other issues.
If and when the parties bridge their differences, the new constitution must be approved in a nationwide referendum before the elections can be held.