There's a display bug with building time. It doesn't counts the days down switching from X days 00 hours 00 minutes to Y days 23 hours 59 minutes but stays X until the countdown reaches 20 hours.
A more detailed explanation from our game investigator James Greer from a earlier thread about this. (Thanks James for all that work btw.)
James
It is just confusing. & hard to explain.
5day build
4d23h59m = first day
3d23h59m = second day (when first day clock resets, shows still 4d until clock reaches 20h then it changes to 3d)
2d23h59m = third day (when second day clock resets, shows still 3d until clock reaches 20h then it changes to 2d)
1d23h59m = fourth day (when third day clock resets, shows still 2d until clock reaches 20h then it changes to 1d)
23h59m = fifth day (when fourth day clock resets, shows still 1d until clock reaches 20h then it changes to just hours)
Does it with them all 2day 3day or 5day builds.
PS: Congrats and thanks Blunion for moderator.