ABOUT THE INVENTOR OF THE MOON PHASE CALCULATOR
At 13 years old I ran away to sea, on trawlers out of Grimsby. I was then called up for the army who taught me electronic equipment repair, which I found easy.
On demob I first repaired computers then did computer hardware design which was never difficult to me. I worked with a team that designed a real time computer system that required the time and date. I knew the days of the months differed and thought leap years happened every 4 years. My boss said to me “ you had better check that before we build this thing”.
I then read some books on the subject. I learnt that it took 4000 years to finally synchronies the calendar with the Sun. I looked up a few different yearly nautical almanacs. The height of the Sun for any particular day only varied at most by about 20 hours. I drew the angles and their dates on cardboard and with a shadow needle casting the Sun’s shadow stayed on the date all day. It became my Sun Calendar, which is presently under construction.
The books I read also said that Meton, an ancient Greek astronomer, calculated that the Moon’s phases repeated every 19 years. The phase today will be the same on today’s date in 19 years time. I contemplated (for 2 seconds) listing all 19 x 365 days phases..... I knew new Moons, or the other phases take 29 1/2 days. Religious Moon Calendars such as Muslim, Chinese and Jewish have months of 30 days then 29 days, repeating. Not knowing where to start I heard that the Book of Common Prayer had a table of The-date-of-the-first-full-Moon-in-Spring for purposes of the determination of Easter.
I took that table and simply listed the full Moons every 30 days and 29 days backwards and forward, and called it ‘The Moon phase calculator’.
Now you know how it works and why it is no more in error than is the ‘Date of Easter’. Norman Darwood.