Here in Australia The Prime minister decides the exact date of the election when it becomes due, but there are some considerations 1st is that it will always be a Saturday and 2nd is they never let it clash with public holidays, school holidays, or a major event like the football finals. This is to ensure that the date is the most convenient for the greatest number of voters.
The electons are held 6 weeks from the day the election is announced, it can be tricky for them as the public holidays and school holidays vary from state to state as can the football finals because some states are Rugby League and others are Australian Rules Football! the Pollies here know not to mess with the public's priories!
We have a Federal election in about 3 weeks time, so we are about 1/2 way through an election campaign and thankfully it will be over soon, and we can not have to listen to them and their campaign bullshit for long!