My grandfather, George Avner Baldwin, was a pilot in the United States Marine Corps Reserve during World War II. He was on active duty from 20 Jul 1943 until 16 Nov 1945. During and prior to this time, he kept a flight log book (as was surely required of all pilots). The contents of this book have been digitized to the PDF linked to below.
There are lots of interesting entries during the time he was in the Japanese theater: dive bombing, anti-submarine missions, and so forth. But, the most interesting entry is on page 32 of the PDF: 03 May 1944. A ring is drawn in the "Remarks" column. We believe this is the day he sent a letter to my grandmother (or learned of her acceptance) asking for her hand in marriage.
George Avner Baldwin's World War II Flight Log Book