05/28/2015 04:51 EDT | Updated 05/28/2016 05:59 EDT

Timeline of Ontario's current labour strife in schools

TORONTO - A timeline of teacher labour strife in Ontario schools during the current round of bargaining:

April 9, 2014: School Boards Collective Bargaining Act becomes law, separating negotiations into local and central talks.

Aug. 31, 2014: Contracts expire for teachers across Ontario.

April 17, 2015: Ontario Secondary School Teachers' Federation says their central talks with the province and the Ontario Public School Boards' Association are at an impasse.

April 20: Central talks with OSSTF resume.

April 20: High school teachers in Durham District School Board go on strike.

April 24: Ontario English Catholic Teachers' Association members vote 94 per cent for a strike mandate.

April 27: High school teachers in Rainbow District School Board go on strike.

May 4: High school teachers in Peel District School Board go on strike.

May 4: OSSTF says central talks are again at an impasse.

May 11: Elementary teachers begin a work-to-rule administrative strike.

May 12: Durham, Rainbow and Peel boards ask the Ontario Labour Relations Board to declare the strikes illegal, saying they are really over central, not local, issues.

May 14: Ontario Labour Relations Board hearing begins.

May 15: Minister of Education Liz Sandals asks the Education Relations Commission for advice on whether Durham, Rainbow, Peel students' school years are in jeopardy.

May 20: Central talks are set to resume with OSSTF.

May 21: High school teachers in Ottawa-Carleton District School Board and Halton District School Board are to begin an administrative strike.

May 23: OSSTF says talks have again reached an impasse and they are applying for conciliation.

May 25: The government tables back-to-work legislation for striking high school teachers in the Sudbury-area Rainbow District, Peel Region and Durham Region. The NDP does not support the bill.

May 26: Ontario Labour Relations Board declares the Rainbow, Peel and Durham strikes illegal.

May 27: High schools in the Durham, Rainbow and Peel districts reopen following the labour board ruling.

May 28: Ontario government passes back-to-work legislation, which ensures high school teachers in the Durham, Rainbow and Peel districts can't strike for the rest of the school year.