In a comedic letter he wrote, An Economical Project (published in 1784), ”to the authors of the journal of Paris”, Franklin mentions something like daylight saving time; instead of changing clocks, though, he suggested ringing church bells and firing cannons, among other things, as the sun rises to maximize the amount of time people would be awake during times when the sun is providing free light. The letter was meant to be a satire, rather than actually suggesting these changes be made.
Here’s an excerpt of the letter:
You often entertain us with accounts of new discoveries. Permit me to communicate to the public, through your paper, one that has lately been made by myself, and which I conceive may be of great utility.
I was the other evening in a grand company, where the new lamp of Messrs. Quinquet and Lange was introduced, and much admired for its splendor; but a general inquiry was made, whether the oil it consumed was not in proportion to the light it afforded, in which case there would be no savoring in the use of it. No one present could satisfy us in that point, which all agreed ought to be known, it being a very desirable thing to lessen, if possible, the expense of lighting our apartments, when every other article of family expense was so much augmented…
I went home, and to bed, three or four hours after midnight, with my head full of the subject. An accidental sudden noise waked me about six in the morning, when I was surprised to find my room filled with light; and I imagined at first, that a number of those lamps had been brought into it; but, rubbing my eyes, I perceived the light came in at the windows. I got up and looked out to see what might be the occasion of it, when I saw the sun just rising above the horizon, from whence he poured his rays plentifully into my chamber, my domestic having negligently omitted, the preceding evening, to close the shutters.
I looked at my watch, which goes very well, and found that it was but six o’clock; and still thinking it something extraordinary that the sun should rise so early, I looked into the almanac, where I found it to be the hour given for his rising on that day. I looked forward, too, and found he was to rise still earlier every day till towards the end of June; and that at no time in the year he retarded his rising so long as till eight o’clock. Your readers, who with me have never seen any signs of sunshine before noon, and seldom regard the astronomical part of the almanac, will be as much astonished as I was, when they hear of his rising so early; and especially when I assure them that he gives light as soon as he rises. I am convinced of this…
Yet it so happens, that when I speak of this discovery to others, I can easily perceive by their countenances, though they forbear expressing it in words, that they do not quite believe me. One, indeed, who is a learned natural philosopher, has assured me that I must certainly be mistaken as to the circumstances of the light coming into my room; for it being well known, as he says, that there could be no light abroad at that hour, it follows that none could enter from without; and that of consequence, my windows being accidentally left open, instead of letting in the light, had only served to let out the darkness…
This event has given rise in my mind to several serious and important reflections. I considered that, if I had not been awakened so early in the morning, I should have slept six hours longer by the light of the sun, and in exchange have lived six hours the following night by candle-light; and, the latter being a much more expensive light than the former, my love of economy induced me to muster up what little arithmetic I was master of, and to make some calculations, which I shall give you, after observing that utility is, in my opinion the test of value in matters of invention, and that a discovery which can be applied to no use, or is not good for something, is good for nothing… [From The Writings of Ben Franklin: An Economic Project]
Much more at the always-interesting Today I Found Out* including this:
Although it’s quite clear he’s joking around in this letter, Franklin was known for putting more subtle jokes in many of his other papers that only the most astute would spot. He was so famous for this that, according to Ormand Seavey, editor of Oxford’s edition of Ben Franklin’s autobiography, when they were deciding who should write the Declaration of Independence, they partially chose Jefferson over the significantly more qualified and respected Franklin, as some feared Franklin would embed subtle humor and satire in it that wouldn’t be recognized until it was too late to change. Knowing this document would likely be examined closely by the nations of the world at that time, they chose to avoid the issue by having the much less gifted writer, Jefferson, write it instead, with Franklin and three others to help Jefferson draft it.
* By the way, of you're starting to think about Christmas presents, I highly recommend their book - I've given out several and they're consistently a big hit.