robust_time_syncing.md

@@ -34,14 +34,18 @@ the time is outside the current Tor network consensus'
 the `valid-after` and `valid-until` fields). When Tor fails to
 bootstrap, Tails is effectively useless for networking.
 
-It should be noted that the clock just has to be off by a few hours
+It should be noted that when using obfs4 bridges, the clock just has to be off by a few hours
 for Tor to become completely unable to bootstrap, and that's not very
 uncommon. Certain OSes (including Windows up to Windows 8 at least)
 set the BIOS clock to the local time, and since Tails uses UTC (and
 assumes the BIOS clock is UTC), this becomes a problem for every user
-but those living in the GMT+0/UTC timezone. Hence this is a very
+who needs obfs4 bridges, and whose clock is set to system time,
+unless they live in the GMT+0/UTC timezone. Hence this is a very
 serious problem.
 
+When connecting to Tor directly or using regular bridges,
+the clock can be off by a few hours without causing bootstrapping trouble.
+
 What we want
 ------------