Iceland uses the 24-hour notation, like the rest of Scandinavia really, but it’s not too uncommon to use 12-hour notation in speak. We tend to mix thing, like

Iceland uses the 24-hour notation, like the rest of Scandinavia really, but it’s not too uncommon to use 12-hour notation in speak. We tend to mix thing, like you’ll tell your spouse that you’ll be going to the whatever at “clock/time twenty” but if they ask what time it is at night you’ll say “it’s eleven”. But news media will use 24-hour notation, so it’s very likely a translation. Honestly I’m sort of curious which countries outside the ones the British “founded” use the 12-hour notation officially.