Continuity mistake: When the helicopter has crashed and the President and Banning are standing outside, Banning removes his radio and earpiece and throws them to the ground. The earpiece is back in the next shot. (00:40:00)
Continuity mistake: Secretary of Defence has her name spelt as "MacMillan" instead of "McMillan" (00:35:00)
Continuity mistake: Throughout the 4x4 chase scene the bullet holes in the windscreen keep changing place. (00:29:10)
Continuity mistake: When Mike is telling the President the route to the chapel, it is a close up and when Mike says "It's a cluster ****" the president is looking at him nodding, but it then cuts to behind Lynne Jacob's and he is staring at the map. (00:12:50)
Continuity mistake: When Banning fights three terrorists when the lights come back on, the 3rd gunman's gun changes from a rifle to a sub. (01:16:35)
Continuity mistake: When the US President gets to London and gets out from the chopper, the sun changes between shots. (00:19:10)
Answer: About a year has passed.