On July 22, I read The Australian and noticed this statement on page 12 under the name of Dennis Shanahan: “There is still a long time to go before the scheduled election in August 2013 but Labor couldn’t have had a worse or more disappointing start.” Then on the commentary page opposite there was a letter from George Harley, of Mount Isa, Queensland, as follows: “Tony Abbott’s worst nightmare must be that he wakes up on election day, November 30, 2013 to find the carbon tax is working, the new tax scales are in place, compensation is welcomed, industry is thriving, the economy is booming and the sky hasn’t fallen. Assuming he is still opposition leader.”

My only comment on Harley’s letter is to note that a November 2013 election is technically possible but I think it is pretty unlikely that Julia Gillard would leave the election to as late a date as Harley nominates. In Shanahan’s case, I dispute the phrase “scheduled election in August 2013”. I hope readers will pardon my pedantry on this.

While the parliaments of New South Wales, Victoria, South Australia and both territories do have scheduled election dates, our federal parliament does not. What we have is section 28 of the Constitution, which reads: “Every House of Representatives shall continue for three years from the first meeting of the house, and no longer, but may be sooner dissolved by the Governor-General.” The 43rd Parliament (the present Parliament) first met on September 28 last year. Therefore it expires on September 27, 2013. Consequently, an election for the House of Representatives and half the Senate could easily be held in August, September, October or November of 2013. Any election sooner than that would be for the House of Representatives only.

However, look at the record. There have only ever been two August elections out of the 43 we have had. It chanced that both were on August 21. The first was on August 21, 1943. The next election was on September 28, 1946 and the one after that was on December 10, 1949. There have only ever been four September elections, in 1914, 1934, 1940 and 1946. So there have been no September elections in the past 50 years. Altogether there have been six October elections — 1929, 1937, 1969, 1980, 1998 and 2004. So there have been four October elections in the past 50 years. For that reason I think it is sensible to say that the next election is very likely to be held in October 2013.

Looking at the records we can say also that an election is unlikely to be held in the same month three years later. It is true that there were elections in December 1903 and December 1906, In December 1919 and December 1922, in November 1925 and November 1928, in November 1963 and November 1966 and in March of 1990, 1993 and 1996. However, that does not make it likely that there will be an election in August 2013.

Speaking of September it is worthwhile to note the following dates for the upcoming September. They are the 7th, 14th, 17th and 28th, this last being the first anniversary of the first meeting of the 43rd Parliament. I have already explained September 28, so let me explain the other three.

The seventh of September is the first anniversary of Julia Gillard becoming our “elected” prime minister. By that I mean on September 7, 2010, Tony Windsor and Rob Oakeshott announced their support for the Gillard government, giving her the 76 supporters in the House of Representatives needed to form a government. The following day The Sydney Morning Herald wrote that “After 17 days of wheeling and dealing , it’s time for the hard part …” followed by the big headline “Gillard buys a second shot at power”.

The full ministry was sworn in on September 14 last year. What, you may ask, is the significance of September 17? It comes from looking at the records and noticing that there were two prime ministers sworn in on June 24, Sir Joseph Cook (Liberal) and Julia Gillard (Labor). Cook was sworn in on June 24, 1913 and he ceased to be prime minister on September 17, 1914. Since Gillard was sworn in on June 24, 2010, she passes Cook on September 17 this year in terms of length of service in the office.

The following seven former prime ministers will then have served for shorter terms than Gillard; Frank Forde (1945) for eight days, Earle Page (1939) for 20 days, John McEwen (1967-68) for 23 days, Arthur Fadden (1941) for one month and nine days, Chris Watson (1904) for three months and 21 days, George Reid (1904-05) for 10 months and 18 days and Joseph Cook (1913-14) for one year, two months and 25 days.

*Malcolm Mackerras is  Visiting Fellow in Political Science, School of Humanities and Social Sciences, the University of New South Wales at the Australian Defence Force Academy in Canberra.