Lengthening Days

I've been paying attention to our ever-changing hours of daylight... in part because my moods are very much affected by sunlight.

Now in January, we are enjoying lengthening days. A few days ago, here in Ottawa, we reached a total of 9 hours of daylight. Our daylight is increasing by 1-2 minutes a day. Yay! Our darkest days, in December, provided only 8 hours and 43 minutes of daylight (from sunrise to sunset). So we've already gained about 20 minutes of light since then.

I've learned a few surprising things as I track when the sun rises and sets.

First, the shortest day isn't just one day. For thirteen days, sunrise and sunset fluctuate together. But our total hours of daylight remains 8 hours and 43 or 44 minutes for about 13 days.

Second, from December 1-18, sunset remained more or less at the same time (4:20-4:21pm) whereas sunrise changed almost daily - moving from 7:22-7:37am. Once we began gaining daylight, the opposite happened; most of the gain happened in the afternoon. The time of morning sunrise didn't change much. The sun rose at between 7:40 -7:42am for 21 days.

Finally, I always thought there would be some consistency between the number of hours of daylight and the time the sun rose or set, regardless of whether the days are lengthening or shortening. But that isn't the case! Yesterday, for example, we had 9 hours and 2 minutes of daylight. The sun rose at 7:40 am and set at 4:42 pm. On November 30, we had 9 hours and 1 minute of daylight - almost the same - but the sun rose at 7:21 am! That's 19 minutes earlier! On that day the sun set at 4:22 pm - 20 minutes earlier.

So many of my misconceptions have been shatteted!