Unix Epoch and PHP's calendar system
I just saw a commit flying past as a response to PHP bug #50155. While right now it is proper to define the Unix Epoch at "1970-01-01 00:00:00 UTC", UTC wasn't actually defined until 1972. So it would be more correct to define the Unix Epoch as "the number of seconds elapsed since midnight proleptic Coordinated Universal Time (UTC) of January 1, 1970, not counting leap seconds." (from Wikipedia). What the bit "not counting leap seconds" means, I've already explained before in Leap Seconds and What To Do With Them.
Similarly, PHP's internal calendar is the ISO 8601 calendar. This is a modification of the proleptic Gregorian calendar. The Gregorian calendar implements the current set of leap years every 4 years, but not every 100 years, but again every 400 years (to get to an average year length of 365.2425 days). Obviously this calendar is only in use since 1582 (some countries adopted it as late as the 1900s), so using days like 1066-10-14 in the Gregorian calendar makes little sense because that calendar didn't exist back then. Now, PHP's ISO 8601-based calendar even modifies the Gregorian calendar by including the year 0. The Gregorian calendar goes straight from -1 to 1 which is a pain to do proper date calculations with. Therefore the ISO 8601 calendar uses Astronomical year numbering.
Life Line
@jamesholden Have you ever seen the Expanse? One of the main characters shares your name!
I walked 4.4km in 51m58s
I walked 8.2km in 1h40m07s
I walked 2.4km in 38m25s
@Edent With your ActivityPub implementation, have you figured out how to allow quote posts for your bot posts yet?
📷 Brown Cap in the Grass
🚩 Herikhuizerweg, Rheden, Nederland
I walked 0.9km in 11m17s
I walked 2.8km in 25m32s
I walked 4.6km in 1h8m02s
I hiked 23.0km in 4h10m15s
I walked 3.9km in 39m07s
After my PHP 8.5 in Leeds last night, it's now time to head to Rotterdam to give the same talk there tonight!
It's cold out here, but atleast the snow is now gone.
I walked 1.7km in 13m18s
📷 Avenue Gardens
🚩 Princess Road, London Borough of Brent, United Kingdom
#AutumnColours #FallColours #Photography
📷 Leafy Entrance
🚩 East Heath Road, London Borough of Camden, United Kingdom
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📷 From Green to Yellow.
🚩 St John's Wood Road, City of Westminster, United Kingdom
#AutumnColours #FallColours #Photography
I walked 9.1km in 1h56m24s
The Secret Maps exhibition at the British Library is well worth a visit!
We went last Sunday and it still runs to January.
📷 Mirror
🚩 The Terrace, London Borough of Richmond upon Thames, United Kingdom
#AutumnColours #FallColours #Photography
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