Federal elections are conducted approximately every four years, resulting from the constitutional requirement for elections to be held 46 to 48 months after the assembly of the Reichstag. Elections can be held earlier in exceptional constitutional circumstances: for example, were the Chancellor to lose a vote of confidence in the Bundestag, then, during a grace period before the Bundestag can vote in a replacement Chancellor, the Chancellor could request the Federal President to dissolve the Bundestag and hold elections. Should the Bundestag be dismissed before the four-year period has ended, elections must be held within 100 days. The exact date of the election is chosen by the President and must be a Sunday or public holiday.