At the winter solstice, the shortest day of the year in the northern hemisphere, night loses the upper hand and the days begin to get longer and longer. At first slowly, imperceptibly, then faster and faster until we reach the middle of spring when each day is three minutes longer than the day previous.
I found this great graph that illustrates the rate of change.
On December 21, the winter solstice, the daily variation is nearly zero, which means that the length of daylight on that day is pretty much the same as the day before and the day after.
Now take a look at today, the tail end of January. Each day is more than two minutes longer than the day previous. Tomorrow's daylight is going to be 2 minutes and 23 seconds longer than today's.
During the entire month of March, each day will be more than three minutes longer than the day previous. That's more than an hour and a half gain in daylight over the month.
You can see that the curve also flatten in March, and at the spring equinox the rate of change begins to slow until we pause at the summer equinox toward the end of June. Just like at the winter equinox, the rate of change is essentially zero, and the difference in daylight between the days is measured in seconds.
At this time the days start getting shorter and shorter, the rate of change accelerating and reaching a peak of around three minutes shorter per day at the end of September, at the Autumnal equinox.
But after that, the rate of change slows and slows as we approach the winter solstice when the rate of change again becomes zero, when we again pause before reversing...and the whole thing starts over again.
I just wanted to share this.