Tijdverschillen tussen Engeland en bezet Europees gebied.
Dit artikel is gepubliceerd in Bulletin Air War 1939-1945 Nr. 99 pagina 26/27 en letterlijk overgenomen uit de uitgave 2001-2002 van het Handboek Studie Groep Luchtoorlog 1939-1945 pagina 45.

Time Calculation 1940-1945 by Rob de Bruin (†) / Great Bookham, Engeland.
I have checked two sources: first my own Whitaker Almanac and I have contacted the Royal Observatory at Greenwich. The situation is as follows:

1: Since 1916 Great Britain (from now on called England) has summertime. In winter they have GMT and in summer GMT+1.

2: Middle European Time (MET), that was the time in the Netherlands during the German occupation, it was equal to GMT+1 and during the summer Middle European Time is equal to GMT+2.

3: The English introduced on February 25th, 1940 their summertime GMT+1. In The Netherlands we had Dutch Time. This means that from February 25th, 1940 it was 40 min later in England than in Holland. From May 16th, 1940 the Germans introduced MET and the Dutch were one hour ahead of the English.

4: In England it was summertime during the war from February 25th, 1940 till October 7th, 1945.

5: To get more daylight it went over to Double British Summertime (DBST). This was during:

1941 May 4th till August 10th.
1942 April 5th till August 9th.
1943 April 4th till August 15th.
1944 April 2nd till September 17th.
1945 April 2nd till July 15th.

During these periods the time in England was GMT+2 and that’s the same as MET (Summertime).

7: To make things more clear some examples:

Date Time in Holland/Germany Time in England
30-05-1940 12.28 11.28
22-06-1941 06.05 06.05
03-11-1942 14.18 14.18
01-04-1943 23.25 22.25
01-05-1943 20.08 20.08
06-06-1944 05.30 05.30
05-05-1945 08.00 09.00

8: The change of time was done in the early Sunday morning hours at 2.00 O’clock.

9: Here follows a list of dates when the German time was equal to British time.

1941 May 4th till August 10th.
1942 April 5th till August 9th.
November 2nd till December 31st
1943 January 1st till March 29th
April 4th till August 15th.
October 4th till December 31st
1944 January 1st till April 2nd
April 4th till September 17th.
October 2nd till December 31st
1945 January 1st till April 2nd