Until the , elections were held on a weekday. In 1938 and in , elections were held on a Saturday. In and , elections were held on a Wednesday. In 1950, the legal requirement to hold elections on a Saturday was introduced, and this first applied to the . Beginning with the , a convention was formed to hold general elections on the last Saturday of November. This convention was upset by Robert Muldoon calling a snap election, which was held on Saturday 14 July . The next year an election could have been held on the last Saturday of November would have been 1996, except the day for that election was brought forward slightly to avoid the need for a by-election after Hawkes' Bay MP Michael Laws resigned in April that year (by-elections are not required if a general election is to take place within six months of the vacancy). Since then, only the and have been held on the traditional day.