I have been confused all the time about it, because Skyteam airlines accept for lounge access within 24 hours international connecting trip of standard depart time or arrive time. For example,

SAN-ATL around 10 pm flight on February 3rd,
ATL-any international destination(except Caribbean area and US territory) around following day(February 4th) next first flight is automatically invited at Sky Club.

However, other case is not allow only Sky Club in my experience. For example,

1. SAN-ATL around 10 am or 2 pm(morning or afternoon departing flight) on February 3rd. Then next day(February 4th) within 24 hours connecting flight - at SAN airport Sky Club is not invited.
2. Any international destination(except Caribbean area and US territory)-ATL(it does not matter what time will be arrived) on February 3rd, then following day(February 4th) even if first flight from ATL-SAN or within 24 hours departing from ATL to US domestic flight is not invited.

Anybody know about it exactly policy? How about SAN-LAX by DL(evening departing flight) on February 3rd, next flight LAX-PVG by MU or TPE by CI flight departing after midnight like as 0:30 am following day(February 4th) or so, SAN airport at Sky Club lounge is not eligible? In other words, between 12 am and 2 am departing international flight(February 3rd) is not possible to invite Sky Club Lounge for US domestic portion(February 4th)?