The episode takes place in April 1941 and is named the same. In Alexandria a messenger announces that the Japanese have attacked Pearl Harbor which didn't happen until 8 months later.
However, this episode does not take place in April of 1941, but spans one year and five months from that date until September of 1942, when the next episode begins (All episodes start on the date of its title and end on the date of the title of the next episode).
Pearl Harbour is not mentioned until 23m07s, when Mr and Mrs Pringle have already been apart for some time, him working in Alexandria and her "sticking pins in a map" at the American Embassy. It is at this Embassy in Cairo, not Alexandria, where an Embassy official, not a messenger, informs Mrs Pringle about the Japanese attack.
However, this episode does not take place in April of 1941, but spans one year and five months from that date until September of 1942, when the next episode begins (All episodes start on the date of its title and end on the date of the title of the next episode).
Pearl Harbour is not mentioned until 23m07s, when Mr and Mrs Pringle have already been apart for some time, him working in Alexandria and her "sticking pins in a map" at the American Embassy. It is at this Embassy in Cairo, not Alexandria, where an Embassy official, not a messenger, informs Mrs Pringle about the Japanese attack.