A second Scottish teachers' union has confirmed dates for strike action in a drive for improved pay.
Members of the Scottish Secondary Teachers' Association (SSTA) will walk out on either 7 or 8 December.
A ballot of the union's 6,500 members saw 96% vote for strike action on a turnout of 71%.
Members of Scotland's largest teachers' union, the EIS, are due to strike on Thursday in a move which will close almost all of the country's schools.
Education Secretary Shirley-Anne Somerville said the Scottish government was committed to supporting a fair pay offer for teachers.
Council body Cosla said it was "working at pace" on a revised pay offer but warned of "extremely challenging financial decisions".