Many busy people have wished for another hour in the day. Just a little more time and we could get everything/that last job, chore, assignment done. Well, someday, there will be a 25th hour in the day.

The earth's orbit is pretty stable as far as the amount of time to orbit the sun, so the length of the year is set. But biologists and geologists have found fossils which indicate the length of the day is changing. Fossil stromatolite coral formations have both annual variations to measure years and microscopic daily rings which can be counted to give the number of days in the year at that time. The oldest stromatolite corals found show there were 424 days in a year 600 million years ago. This means there were only 20.7 of our hours in a day at that time. By 350 million years ago there were about 22 hours in each day and 398 days in the year.

How could the earth's rotation slow down over time? One theory says tidal friction from the moon could do the job, and that we would have an 8-hour day if the earth had no moon. The fossil corals data is given from 135 to 600 million years ago in my '88 freshman geology book. The data form a slightly curved line, but I used a straight line for recent data, giving this equation:

Million years = -11.414 x (days in year) + 4,168.76

For the earth to orbit the sun in the same actual time, but rotate
slower, we can calculate the number of days or hours by a simple ratio. Twenty-four hours times 365.23 days divided by twenty-five hours gives a 350 day year. Then, plugging the 350 days per year in the fossil coral equation gives 173.9 million years. The 25 hour day should occur in about 175 million years.
 

Days per Year   Hours per Day   Time
    424             20.7        600 mil yrs BP
    398             22          350 mil yrs BP
    381             23          175 mil yrs BP
    365.23          24          Today
    350             25          175 mil yrs future

If the time scale above is mind-boggling, meditate on the current gene-splicing fad. Chicken genes have already been added to potatoes for increased disease resistance, human genes spliced into pigs to make leaner meat, and arctic flounder genes inserted in various fruits and vegetables to protect against freezing. And what about the enzymes produced by coliform bacteria by splicing? One is suspected of causing 27 deaths and 1500 serious illnesses ---- amino acid L-tryptophan, produced by genetically altered bacteria from Japan's Showa Denko company. Will there be any intelligent life on earth 175 million years from now?