A Million Seconds Ago Was July 24th, a Billion Seconds Ago Was 1988?

Around August 5 2019, a text meme began circulating on social media comparing a “million” to a “billion” by pointing out that a million seconds prior was the month before (specifically, July 24) and a billion seconds prior was sometime in 1988.

This striking difference seems intended to illustrate how vastly wealthy “billionaires” truly are — and how conflating millionaires with billionaires is inherently faulty. It seems that the specific “July 24th” and “1988” numbers originated with an August 5 2019 thread published to r/AskReddit — “What is a true fact so baffling, it should be false?”

A highly-upvoted comment made on that day used those specific dates in time to illustrate the point. The comment has since been edited, but remains more or less in the same format:

In their edited comment the user leaves original and updated calculations, revising the “billion seconds” date from 1988 to November 1987:

A million seconds ago was week before last, July 24th. A billion seconds ago was 1988 1987.

. . .

ed: Made some rounding errors. We’re looking at November, 1987.

A separate user lifted the claim and uploaded it as a new thread in r/ShowerThoughts (removing it after other users exposed it as a repost):

From there, the comment inspired additional reposts across social media, identifiable as such thanks to the use of similar time-based references:

Those tweets, shared one day later, changed “July 24th” to “the last week of July” to partially address the claim going quickly stale, as roughly two weeks passed between that date and the date of the Reddit comment, rapidly altering the accuracy of the post. Based on the math used in the August 5 2019 comment, the “million seconds” date would be around July 31 2019, one week later.

That, however, is assuming the claim is correct. A similar meme shared to me.me in April 2017 featured radically different calculations, placing one billion seconds prior in 1959, not 1985 or 1986 — a difference of nearly three decades:

The text of the older meme appeared to have a specific focus, illustrating the purported growth of America’s national debt at some point before the meme was created:

A billion seconds ago, it was 1959.

A billion minutes ago, Jesus was alive.

A billion hours ago, our ancestors were living in the Stone Age.

A billion days ago, no-one walked on the earth on two feet.

A billion dollars ago, was only 8 hours and 20 minutes, at the current rate of government spending.

In October 2017, the claim appeared on r/ShowerThoughts, asserting that a million seconds was 11 and a half days, and a billion was roughly 31 years:

And a September 1986 letter to the editor in the New York Times made similar claims about millions, billions, seconds, and the national debt:



Why not think of it in terms of seconds, I asked myself? A trillion seconds would have to be years, probably many years ago. I made a wild guess. As it turned out, I wasn’t close. I found that 1,000 seconds ago was equal to almost 17 minutes. It would take almost 12 days for a million seconds to elapse and 31.7 years for a billion seconds. Therefore, a trillion seconds would amount to no less than 31,709.8 years.

Claims about the duration of a million seconds versus a billion seconds seemed to frequently follow the same ratio [PDF], with a million seconds provided at between 11 and 12 days, and a billion at about 31 years. But it wasn’t uncommon for rumors based on incorrect math to circulate for decades, as this rumor circulated.

We know that there are 60 seconds in a minute, 60 minutes in an hour, and 24 hours in a day. There are roughly 86,400 seconds in a day — (60*60)*24 = 86,400. Dividing 1,000,000 seconds by the 86,400 minutes in a day returns a figure of 11.54 days, or just over 11 and a half days. On August 13 2019, a million seconds earlier was August 1 or 2 2019.

To calculate the second figure of a billion seconds, we can multiply the number of seconds per day (86,400) by the number of days in a year (365) to get a total of seconds per year — 31,536,000. A billion of any unit is equal to a thousand millions. So our yearly figure of 31.5 million seconds fell far short of a billion seconds.

If we divide one billion (1,000,000,000) by 31,536,000, the result is 31.7. Consequently, a billion seconds is just over 31 years — but the .7 refers to seven tenths, and we’re accustomed to calculated years in units of 12 months. So we have to calculate ten percent of 365 to get the correct decimal unit, one-tenth of 365 or 36.5 days.

Then we have to multiply the number of tenths (seven) by that number (36.5) to get a number of days, which rounds out to 255.5 days. A billion seconds prior to any date is 31 years and 255.5 days prior to it. Another approach is converting that all to units of days, (365*31) = 11,315. And 11,315 + 255.5 = 11,570.5. So 11,570.5 days is equal to a billion seconds.

From there, we have a starting calculation, today’s date minus 31 years and 256 days (rounding up). Using a duration calculator, we calculated the distance between the date of the Reddit comment (August 5 2019) and 256 days prior to it to get a close ratio for the .7 part. The date 256 days prior to August 5 2019 was November 24 2018. From that, if we subtract an even 31 years, the date is November 24 1987.

The user’s edited comment was mathematically correct on both counts as of August 5 2019 — a million seconds prior was 11.5 days earlier, and a million seconds is always 11.5 days. A billion seconds earlier was 31.7 years prior, or 31 years and 255 days, falling on November 24 1987.

Updating the calculations by a week for August 13 2019, a billion seconds prior was still the end of November 1987. However, a million seconds prior to that date was either August 1 or 2 2019. The calculations are broadly accurate, but constantly changing because of the relative brevity of a million versus a billion seconds.