Currently Chaos raids are happening between 3am to 8am eastern, so they are uncontested. Making defending a nearly 24 hours job.
Before anyone says anything there are raids that do happen during other hours of the day but the primary bulk of raids is in the times I posted above.
Taken straight from PVP Feedback thread :
Deeds can now only be raided during raid windows, villages will be able to pick the time this window opens and this can only be changed every 2 weeks. The window duration is dictated by villager/alliance count and if it's located in the safe zone or not. You will be able to view the window and how long till it starts by right clicking any wall/fence on the deed from any distance. Starter villages will be 100% unraidable.
Raid windows will be around 2 hours for safe zones and 6+ hours outside them.
The raid windows are focused on giving players control over when people can attack so defending it is not a 24 hour job and people are not trying to find off hours to attack with no defenders.
Balancing pvp hasnt been very hot on the to do list but this is mechanic that has already been tried and proven to be good.