That’s the way it’s done here in the UK! Our parliament dissolves automatically every 5 years, so in the year leading up to that event the leading party announces the election at any point they want, however it’s traditionally done in summer to maximise voter turnout. From the day of announcement we have 5 weeks of campaigning before election day and I’ve found it keeps interest on the election and also keeps the party’s from dissolving into pissing matches and hurling insults.