The Education ministry has gazetted .
The development comes despite resistance from Knut secretary general Wilson Sossion who has argued the new dates will impact negatively on learners.
Education CS Fred Matiang’i said the circular for the new changes has been released to county directors of education for immediate implementation.
The CS said in Mombasa on Tuesday that all parties in the sector were consulted when the changes were drafted.
Matiang'i, during the opening of the secondary school head teachers conference, said the changes will restore sanity in the Education sector.
He said the resolutions were arrived at in a meeting attended by Knut chairman Mudzo Nzili, and Kenya Union of Post Primary Education Teachers (Kuppet) officials.
The CS said he will not be distracted by "few individuals yet everyone was involved in the process", adding that the Basic Education Act gives the cabinet secretary powers to review and fix term dates.
But Sossion has opposed the changes arguing that they will affect teachers’ programmes within the various institutions of learning.
Matiang’i said school heads have welcomed the changes further indicating that more parties including the EACC will now be involved to tackle cheating.
The Ministry seeks to restore public confidence in the Kenya National Examination Council.
The new calendar also bans social activities in the third term. This affects prayer and visiting days; half term breaks, sports, prize-giving ceremonies and annual general meetings.