The ban starts on March 21st, which would mean Thierry missing the matches against West Ham (or possible cup replay), Sunderland and Charlton, but he'd be back for the Tottenham and Man Utd games. Having said that, the Charlton game on 1st April would have to be moved if Arsenal reach the Champs League quarter finals (1st leg April 2nd or 3rd), so the Tottenham game could (will, we hope!) be affected.

We suspect that the date of 21st March is based on the 2 week period between red cards and subsequent bans. The FA's own site seems to suggest the ban is definitely scheduled to start March 21st.

But other reports say the ban starts with immediate effect, this would be in line with the normal procedure for hearings of this sort (because it's well over 2 weeks since the incident concerned). This would mean that if Arsenal don't appeal against it by the weekend, Thierry will miss the Newcastle FA Cup quarter final on Saturday, and the next 2 Premiership matches too (Villa and West Ham).

Arsene Wenger called the ban "very harsh" and said Arsenal would consider appealing. Perhaps knowing this influenced the FA's decision to hold the ban off till 21st March, but there's no mention of it on the official Arsenal site, which confirms the 21st March start date. Presumably they're still considering. But given that the Man Utd match could be hit if they delay with an appeal, perhaps they'll decide against it.

Patrick Vieira's charge of elbowing Jimmy Floyd Hasselbaink will be heard next week.

Rupe adds...
...as we suggested above, Arsenal did decide against the appeal. And as a result, the FA changed their minds about the date the suspension should start! The people who got it wrong first time, turned out to be right. See this story