Bertie Ahern favours a general election in mid-June, but believes the coalition will stay in power until next year.
Attending the Fianna Fáil ard fheis in Dublin, the former taoiseach suggested that summer would be the best time to go to the polls.
However, he said he believes the Government will remain in office until next year, predicting the "last Thursday or Friday in February" as the election date. He said:
Wishing new Taoiseach Simon Harris well, Mr Ahern said he has a lot of experience age, having worked in the Department of Health.
"He might be 37 but he has still put in a lot of years," the former Fianna Fáil leader said.
Asked what advice he would give the new leader, Mr Martin said: "Take a small number of issues and do the best you can on those issues.
"The one thing when you are Taoiseach, you get up in the morning and the day never runs as you think it will," he said.