Convert Seconds & Days Since Year 0-1970
On this page some variants of the Unix epoch:
- Seconds since year 0 (MySQL compatible)
- Seconds since January 1, 1 AD
- Days since year 0 (MySQL compatible)
- Days since January 1, 1 AD
- Days since January 1, 1900, used for Excel DAY functions
- Days since January 1, 1904, formerly used for Excel DAY (Macintosh)
- Days since January 1, 1970, Unix epoch
Seconds Since Year 0
This tool converts seconds since year 0 to human-readable dates.
It's compatible with MySQL's
TO_SECONDS function (MySQL 5.5+).
Year 0 is defined as 0000-00-00 00:00 GMT. Please note that this is not a valid date! There is no year 0.
At this time there are ~63778861255 seconds since year 0 (6.378*1010).
Visit the homepage to convert to/from seconds since 1/1/1970.
Convert seconds to normal date:
Seconds Since 0001-01-01 AD
This tool converts seconds since January 1, 1 AD (extrapolated Gregorian calendar) to regular dates.
There were ~63747238855 seconds since Jan, 1 0001 (6.375*1010).
Days Since Year 0
Compatible with MySQL's
TO_DAYS function (MySQL 5.5+).
There are 738181 days between 0000-00-00 and today (Tuesday, Jan 26, 2021).
Convert days to normal date:
Days Since 0001-01-01 AD
There were 737815 days since January 1, 1 AD.
Days Since 1900-01-01
There were 44220 days since January 1, 1900.
This number (+2) is used in the Microsoft Excel date functions such as
Note, Excel's serial number is 2 higher than the number on this page.
- In Excel January 1 is serial number 1. In this converter midnight January 1, 1900 is 0, after 1 day it is midnight on January 2. To correct this you have to add/subtract 1.
- Excel incorrectly sees 1900 as a leap year (for compatibility with Lotus 1-2-3) so you have to add/subtract 1 to all days when using in Excel. Also see: Excel incorrectly assumes that the year 1900 is a leap year
Days Since 1904-01-01
There were 42760 days since January 1, 1904h.
This number (+1) was used for Microsoft Excel date functions on earlier versions only for the Mac.
Excel 2016 for the Mac uses 1900 as a default start date.
Days Since 1970-01-01
There were 18653 days since January 1, 1970, the Unix epoch.
Please note: This page might be cached, the current day uses GMT/UTC time.