193.This section makes changes to the timing for service of section 21 notices and the bringing of possession proceedings in relation to section 21 notices. The effect of the section is that a notice under section 21(1) or section 21(4) cannot be brought during the first four months of a tenancy, with the exception of replacement tenancies, as defined in section 21(7) of the Housing Act 1988, or tenancies arising under section 5(2) of the Housing Act 1988 (periodic tenancies arising at the end of a fixed-term tenancy). The section also provides that proceedings for an order for possession may not be begun later than six months from the date of service of a notice under section 21(1) or section 21(4) of the Housing Act 1988, with an exception where a notice given under section 21(4) requires more than two months’ notice to be given, in which case proceedings for possession may not be begun later than four months from the date specified in the notice.