Mayor Bill de Blasio on Sunday sought to burnish his legacy as he takes steps toward a run for governor, promoting his education record and statewide year-round schooling proposal.

During campaign-style speeches at churches in Harlem, the lame-duck mayor touted his newly announced proposal to give New York State students an option for summer school and expand after-school programs for them — initiatives funded by increased taxes on the rich.

“Here’s what I want to create in this city in this whole state … Every family should have a guarantee, every family should know that your child can be in a safe, positive place, not just until the school day ends at 2:30 or 3 o’clock, but until the end of the afternoon, the end of the workday. It should be a guarantee,” he said at Bethel Gospel Assembly Church. “It should be a right for every family to know that, if you want your child there the whole day long, you can have that.”

De Blasio then explained to parishioners that he wants all Empire State pupils to be able to spend their summer days in “beautiful, positive” settings modeled off The Big Apple’s new summer-school program City Hall dubbed “Summer Rising.”

“How about every family has a right in summer, if they want their child in a positive environment, if they want their child yes and the recreation, arts and culture that the fun, but also to get academic support throughout the summer to build them up?” he said from the church pulpit. “Remember, we used to hear about summer school, which was like if something went wrong, you got sent to summer school. Now, you get the idea. [and] puts it on its head, and says, ‘Let’s make summer a beautiful, positive time and give a universal right to all parents.”

De Blasio leaves City Hall towards the end of 2013, but he also talked about his campaign to implement universal prekindergarten across the five boroughs.

“The establishment in this town said it would never happen. However, you believed that it would never happen. And today, a New York City is calling a pre-K program a “universal right” for all children. And we saw it worked and we saw what it did for families,” he boasted to applause from congregants at First Corinthian Baptist Church. “And now we’re almost to the point of we’re gonna have universal 3K — every 3-year-old for free, uplifted, supported, every family knows they can depend on.”

The mayor’s pair of church appearances comes after on Thursday he released his statewide educational proposals, while stopping short of announcing a bid against Gov. Kathy Hochul and a growing field of Democratic contenders in the June gubernatorial primary.

“In the weeks ahead,” the mayor responded on MSNBC’s “Morning Joe,” when asked when he will make his gubernatorial run official, “I’ll certainly have more to say about that.”

Earlier this month, Mayor de Blasio formed a candidate committee with the state Board of Elections, and after he in recent months signaled he will launch a longshot bid to serve as the state’s chief executive.

State Attorney General Letitia James — whose monumental sexual harassment probe led to Gov. Andrew Cuomo’s resignation — Public Advocate Jumaane Williams and Hochul have already declared they will run in the 2022 race.