You may have heard there was a giant attack last night (the 23rd). This post is to help you get an idea of how informed your character would be.
If you live in Lantern Waste and are a warrior: you know there was an attack and were probably part of the defense against it. It was centralized around the western Waste (mostly the Gathering Circle and the Cavern of the lists) so if you feel the need to say your warrior character was not involved, your reason should probably be that they were pretty far away from that area and somehow word didn't get to them (or perhaps they rushed to the border to defend against any potential lagging giants). But probably you were involved. You know Nevarre was captured and is believed to still be alive but (very possibly mortally) injured.
If you live in Lantern Waste and are not a warrior: by now you know there was an attack and you have probably been told to remove yourself and your family to a secure location (that is, a place where giants won't fit, or a place further from the border). There's a good change you know about Nevarre as well.
Everyone else: Wait at least a day for each region between you and Lantern Waste to act 'informed'. I know birds could carry the news faster, but unless you are a VIP like the Pevensies, it's safer to assume you heard by a slightly slower route. If you are a non-warrior character it will probably take you longer to learn details. So: Madderholt/Upper Plains would probably know by the 24th. Barfield/Western March will find out around the 25th. Sted Cair/Great Woods/Bergdale will probably not know until at least the 26th, unless you get an IC reason to learn something (like troops are leaving the castle in droves). Archenland, you'll probably only find out about this if Archenland is asked to help-- at least for a few weeks.
Remember, this is the minimum amount of time, especially for those of your further out. If you are in Lantern Waste you almost definitely know, but the further out you are, the more conceivable it is for you to be ignorant.