He taught high school math in rural Saskatchewan before returning to Saskatoon in 1969, where he continued to teach, working at Evan Hardy, City Park, and Marion M. Graham Collegiates.

Dayday's priority during this period was on keeping property tax increases low, emphasizing what he saw as fiscally responsible governance.

By the late 1990s, the Saskatoon Police Service was embroiled in controversy over the practice of Starlight tours, or the abandoning of Indigenous residents outside of the city in freezing temperatures.

After the New Democratic Member of Parliament for Saskatoon-Rosetown-Biggar, Chris Axworthy, resigned in the summer of 1999, Dayday ran in the by-election as the Liberal candidate.

[3] In 2012 Dayday announced his intention to run again for Saskatoon mayor, challenging three-term incumbent Don Atchison.

[7] Wolf would go on to lose narrowly to Atchison, who secured a fourth term, equaling the mayoral runs of Dayday and Wright.

[11] After his long stint as mayor, Dayday worked as a business consultant and was a member of the Board of Directors for the Saskatoon Airport Authority.

[3] Several streets in the Aspen Ridge neighbourhood of Saskatoon, most notably Henry Dayday Road, are named in his honour.