Years after the former Conservative government did away with the mandatory long-form census, it seemed as though Canadians were eager to dive into the national questionnaire.

This year’s census was such a hot topic on Twitter on Monday, that the hashtag #Census2016 was trending nationwide.

Marc Hamel, director general of the census program, also confirmed to CTVNews.ca that the census website did go down for a short while Monday night due to the influx of traffic.

This week, Canadians began receiving a census access code, which allows them to access the census online. But those who were hoping to complete the questionnaire on Monday night were disappointed when the high volume of traffic crashed the government website.

May 10 is ‘Census Day’

Statistics Canada says more than 15 million households will receive census letters over eight days, along with reminders to either fill a hard copy of the form, or online.

Every home will receive a short-form questionnaire, while one in every four homes will receive the long-form census.

And while Canadians can start filling out the census now, they are supposed to use May 10 as a “reference day,” Hamel said -- meaning those planning on moving this week should answer the questions as if they are living at their new residence.

Hamel said people are encouraged to fill out the form as soon as possible, and that after May 10, the government will begin sending out reminders.

Those who ignore the reminders might get someone knocking on their door a month from now.

“But the vast majority fill out the census in May,” he said.

The census is mandatory, and persistently avoiding it could come with a fine of up to $500 or three months in prison, Hamel said. In 2011, there were over 60 cases that were prosecuted – most resulting in fines or a court order to fill out the form.

“One person was sent to jail, basically because he refused the suggestions by the court to complete the form,” Hamel said.

The gender question

This year’s census asks Canadians to identify their sex, but only lets users respond with either “male” or “female”.

For those who identify as neither, Hamel offers a workaround: skipping the question and explaining why in the comments section of the questionnaire.

“We’re reviewing possible changes to the question in the future,” Hamel said. “But we offer this alternative for the time being.”