Inconsistently.
Jane's network has kept all the Bells' worlds - and every other world with a Janepoint stuck in due to its being attached to Downside - in temporal sync, but when Jane spluttered for just a moment, that was shot to hell.
Peace lost three seconds, because it was where Aegis torched; after that process was complete, Jane was there again. And as soon as a door between Peace and Milliways appeared, she could sync to her ansible hub in the Belltower and, from there, to everywhere else.
Atlantis and Sunshine each stand at about a minute apiece: Shell Bell's aura and Juliet's local copy of Jarvis both enabled them to get to Milliways immediately, pausing their homeworlds as standard for occasions when someone walks into the bar. Shell Bell's the one who connected Peace.
Everyone else was running on luck.
Luckiest is Rainbow, which lost only five hours.
Next is Alethia; in spite of Sherlock's mishap, it's fared reasonably well, spending only six weeks isolated.
Syntropy's just a little worse - seven weeks.
Origin waited two months.
Eos waited three.
Thilanushinyel, ten.
Everyone else is out a decade at least. Samaria's ten years, almost ten and a half.
Aurum is out eleven.
RĂªverie has been separated for sixteen years.
All the Bells - and Elspeth, who was stuck in Downside for a day and a half on her end and whose mother was very upset - are collected in the Belltower, as are two Bell-attached Sherlocks who happened to be along for the ride. They all memorize this list of numbers. Aegis replaces her earpiece. And then they all go home to notify their loved ones and staff that there's a party cooking in the Belltower.
(Shell Bell, who has no particular cause on her own account to be distressed, sends her Sherlock to invite Tony in while she refits the Belltower to suit a party of a peal of Bells and their larger-than-last-encountered families and circles of friends.)
"...no," she says, "have we met? We haven't met, we would've gone through this whole rigamarole if we'd met, unless you're from one of the worlds that got mega cut off and we met when you were like two, and holy shit, you're that cute kid who was running around the first Bellparty, aren't you."
Kerron peers at some flying colorshapes. "Well, in case there's any of it left and you wouldn't want it to suffer some awful fate later, I should probably warn you relatively upfront that I'm chronologically twelve, in case that affects any... ice-cream-related interests... I may wish to hear lots more about."
"I am very conveniently warmish!" he agrees. Up they go. Yep, somebody prescient has separated this floor into "airlocked" chambers. This is the Belltower and pastwatching doesn't work at Milliways, so there is no feature inviting people to donate their bodies to pornography, just indications of vacancy or lack thereof.