fix: match day counting behavior with Day.js in English locale

[0ui]

I ran into an issue when counting days where the behavior seemed a little odd to me. I noticed that Day.js was cited for reference and confirmed that the behavior in Day.js is different. Essentially if I compare Monday 8:00AM to Wednesday 8:01AM it will return 3 days ago instead of 2 days ago and it makes day counts feel 12 hours too early.

	timediff	Day.js
Day 1	00 - 35 (35hrs)	00 - 36 (36hrs)
Day 2	35 - 48 (13hrs)	36-60 (24hrs)
Day 3	48 - 72 (24hrs)	60-84 (24hrs)
Day 4	72 - 96 (24hrs)	84-108 (24hrs)

Day.js has regular 24-hour intervals after the first long day, but timediff has a shorter 13-hour second day due to not offsetting for the long first day.

This change makes all the intervals a regular 24 hours after the first and updates the tests to reflect the changeover time. Hope that all makes sense. I could also try to adjust the other locales if that's helpful. Cheers!

[0ui]

Not sure if it was the intent to entirely match with Day.js behavior, but when I compared the existing tests with Day.js, I found about 14 that didn't align with the output, largely due to precision around months/years, but at the precision level expected for a library like this they all seem very fixable.

There are also discrepancies in inclusiveness forward and backward in time. If that would be helpful, I could also assist in matching that behavior in a separate PR.