On the same subject - the reason why UK elections are always held on Thursday.
"Since 1918 a General Election has always been on a Thursday, except for 1918, 1922, 1924 and 1931. The reason for choosing Thursday, it is said, was as follows. On Fridays the voters were paid their wages and if they went for a drink in a pub they would be subject to pressure from the Conservative brewing interests, while on Sundays they would be subject to influence by Free Church ministers who were generally Liberal in persuasion. Therefore choose the day furthest from influence by either publicans or Free Church clergymen, namely Thursday.