HC Deb 21 November 1968 vol 773 c307W
45. Sir E. Errington

asked the Postmaster-General what was the date when, the reason why, and the conditions under which the time of posting was omitted from certain Post Office date stamps on envelopes.

Mr. Stonehouse

Clock times shown in Post Office date stamps are provided for control purposes. The times are omitted during the Christmas period, and since 1922 they have not been shown on some lower paid envelopes dealt with in off-peak periods.