Confirmation SMS will be sent to those who are registered.
The longer hours, including on holidays, are expected to ease the rush at hospitals and medical centres.
The Central Vaccination Centre has already sent an SMS about the new appointment time to those who had made reservations.
The Central Vaccination Centre is a collaboration between the Public Health and Transport Ministries, utilising 14,000 square metres of space at Bang Sue Central Station as the main free Covid-19 vaccination centre, capable of 10,000-20,000 jabs per day.