It's the first day of one-day strikes from the province's public elementary teachers but the GTA will be seeing its affects for the first time on Thursday.

The Elementary Teachers' Federation of Ontario officially announced that's when York Region teachers will be walking out.

York Region District School Board knows parents may be feeling slightly panicked when they hear about the one day strike, so it's laying out it's plans for Thursday. It says not only classes will be cancelled but also before and after school care programs and teacher supervision after school as well.

Spokesperson Licinio Miguelo says they had been anticipating the union would do this soon, so they have been prepared for some time. He says messages are being sent home to parents to warn them.

He says 171 schools are affected at the board, with 5,000 teachers are expected to walk out.

Two other boards will be hit by walk-outs on Thursday as well: Trillium Lakelands in Muskoka and Renfrew near Ottawa.

The Avon Maitland and Ontario North East school boards are striking Monday, and the Niagara and the Keewatin-Patricia District School Boards in northwestern Ontario on Tuesday. On Wednesday, the Ottawa-Carleton District School Board says it will face a teachers' strike.

"Today, the Elementary Teachers’ Federation of Ontario has disrupted nine years of labour peace over a disagreement about pay," Premier Dalton McGuinty said in a statement on Monday. "It’s regrettable that students miss any time learning, and it’s unfortunate that families will need to make alternate arrangements."

The union has been giving parents 72-hour notice.

(with files from James Moore)