"How old are Bill and Charlie?" someone asked Jo. Very simple question. Her response to that simple question was just as simple. Charlie is two years older than Percy, and Bill is two years older than Charlie. Simple. So what's the big deal?

Unfortunately, this answer just doesn't work. The most obvious problem is that if Charlie were two years older than Percy, he would have been in his seventh year when Harry came to Hogwarts. Ron, during that first ride aboard the Hogwarts Express, tells Harry that Charlie has already left. Even if Ron hadn't said that, we would have know if Charlie were still at Hogwarts with Harry because he would have been at the station with the rest of the family. Since he was a Prefect, we would have seen him heading off to the Prefect's carriage along with Percy. And we certainly would have seen him play Seeker instead of Harry. No, Charlie just can't be only two years older than Percy.

Well, just a moment. There are a couple of ways that he still could be. It's perfectly possible for Charlie to be two years apart in birth but three years apart at school. That all depends on when their birthdays fall. We know that Percy was born on August 22, which unfortunately makes him one of the youngest in his class. The fact that he didn't learn Apparition until the summer after he left Hogwarts reinforces the idea that he's on the younger end of his class. In order for this scenario to work, however, he would have to be one of the oldest. So while this is still possible, it is highly unlikely given the facts that we have that Charlie is two years older but three school years apart from Percy.

The other possible scenario actually has some canon support. Charlie might have spent his last year studying abroad, getting first hand experience. Ron says that "Charlie's in Romania studying dragons..." (PS6) which could certainly be interpreted as meaning that he's still finishing up his schooling. There are a couple of snags to that theory, however. First of all, if Charlie were still a student, Ron wouldn't say "Bill and Charlie have already left..." He would have said "Bill's left and Charlie is finishing up with a year in Romania." The term "left" is roughly the equivelent of the term "graduated" in the US. Also, if Charlie were taking a study year abroad, certainly this unusual fact would have been mentioned at some point. Wood, who was looking back on a dismal previous season, would have complained about not having his star Seeker available, certainly. Instead, he, like everyone else, talks about Charlie as if he's part of the fairly distant past, right along with the fond memories of the last Gryffindor winning of the Quidditch Cup, seven years before.

And that brings up the most difficult details of all: that last Gryffindor win. We know when it was. If we examine the various quotes in the books which talk about it, perhaps we can also determine where Charlie fits into the tale.

The entire history of the Quidditch and House Cups for the past decade is a bit hard to sort out. Here are the facts we have to work with:

"I tell you, we're going to win that Quidditch cup for sure this year," said Fred. "We haven't won since Charlie left, but this year's team is going to be brilliant."
[Fred said this when he heard that Harry would play Seeker, in book one, so the last year they won was Charlie's last year. Alternative interpretations are possible but not very likely]

If they won their next match, against Hufflepuff, they would overtake Slytherin in the house championship for the first time in seven years...As the match drew nearer, however, Harry became more and more nervous, whatever he told Ron and Hermione. The rest of the team wasn't too calm, either. The idea of overtaking Slytherin in the house championship was wonderful, no one had done it for seven years, but would they be allowed to, with such a biased referee? (PS)
[this certainly sounds like "house championship" refers to the Quidditch cup, although since the Quidditch Cup cummulative score apparently gets added into House Points, defeating Slytherin in Quidditch would help them win the House Cup as well]

"[T]he Great Hall was already full. It was decked out in the Slytherin colors of green and silver to celebrate Slytherin's winning the house cup for the seventh year in a row. A huge banner showing the Slytherin serpent covered the wall behind the High Table. (PS)
[so Slytherin have won both the Quidditch Cup and the House Cup for seven years straight at this point...although in a few moments, Gryffindor will turn out to be the winner of the House Cup instead]

"Gryffindor hasn't won for seven years now" Oliver Wood, at the beginning of the 1993-1994 school year
[off by one year, but perhaps he's taking the cancellation of last year into account]

"'Seriously,' said Professor McGonagall, and she was actually smiling. 'I daresay you'll need to get the feel of it before Saturday's match, won't you? And Potter - do try and win, won't you? Or we'll be out of the running for the eighth year in a row, as Professor Snape was kind enough to remind me only last night ...'"
[this is from book three, so it's the '94 Cup they're hoping to win after seven previous losses -- but is Snape including the missed year in this?]

Gryffindor hadn't won the Quidditch Cup since the legendary Charlie Weasley (Ron's second oldest brother) had been seeker (PA)
[Although this can be interpreted differently, it seems most likely that this means that the last time Gryffindor won the cup was the last time Charlie was on the team]

Gryffindor House, meanwhile, largely thanks to their spectacular performance in the Quidditch Cup, had won the House championship for the third year running (PA).
[This time the phrase "House championship" refers to the House cup; winning the Quidditch Cup obviously adds points to the House Cup championship]

But what year was he at the time? If we go with the World Book Day interview, we need to push Charlie's last year to 1990, so he would have only been in his 3rd year. If, however, we use these book references, we would put Charlie most likely in his 7th year, Gryffindor losing their hold on the Cup when he left.

This chart pulls together all of this information as well as can be done. Some facts contradict others and Jo's comment in the WBD interview contradicts every reference in the books. Where does Charlie fit on this chart? All we can say for sure is that Charlie played in the 1983-1984 school year and that he had to be in at least his second year. From several of the references we can also say with a fair amount of confidence that the last Gryffindor Quidditch Cup win was Charlie's last year at Hogwarts.
 

school year	Cup winners (Quidditch/House)	Gryffindor team notes	other teams and players	Where's Charlie?
1983-1984	/? ("The idea of overtaking Slytherin in the house championship was wonderful, no one had done it for seven years..."  This is seven years before that statement was made. Charlie HAD to have been on the team this year, since "Gryffindor hadn't won the Quidditch Cup since the legendary Charlie Weasley...had been seeker.")			Charlie (at least 2, more likely 7 and captain)
1984-1985	/NOT
1985-1986	/
1986-1987	/
1987-1988	/
1988-1989	/	Wood? (2)		The youngest Charlie can be and still match the facts in the book would place him in his seventh year here. It's not clear why, with a Seeker who could have played for England, Gryffindor lost the Quidditch and House cups every single year.
1989 -1990	/	Wood (3)
1990-1991	/	Wood captain (4) Angelina (2) Alicia (2) Fred (2) George (2) This was a bad team. In the fall of 1991, McGonagall says: "Heaven knows, we need a better team than last year. Flattened in that last match by Slytherin, I couldn't look Severus Snape in the face for weeks...."		Now we're getting close to the years which match what Rowling said in the EBF interview. If we say that Charlie was two years in age but three school years above Percy, Charlie would have been in his seventh year this year. Since we know the team was lousy, it seems likely that Charlie wasn't part of it.
1991-1992 (SS)	/ Slytherin's last year of winning the Quidditch Cup. This would have been their seventh year in the row of winning the House Cup. They lost it when Dumbledore added a large number of points to Gryffindor after Harry's defeat of Quirrell.	Wood captain (5) Angelina (3) Alicia (3) Fred (3) George (3) Harry (1) Katie (2) "We should have won the Quidditch cup [this] year. We're easily the best team. But unfortunately - owing to circumstances beyond our control - " Oliver Wood, refering to the fact that Harry was in the hospital wing and they played the last match of the 91-92 scool year a player short	Marcus Flint (6) Terrence Higgs (7?) Adrian Pucey Derrick Bole	If JKR is correct in the WBD interview, Charlie was in his seventh year here, when Harry was in his first. But Ron said on the Hogwarts Express that Charlie has already left, so this really doesn't make sense. He's in Romania studying dragons, which might indicate that he's finishing school there. But that still doesn't work with the fact that Charlie was on the Quidditch team in 1983-84.
1992-1993 (CS)	tournament cancelled none/	Wood captain (6) Angelina (4) Alicia (4) Fred (4) George (4) Harry (2) Katie (3)	Flint (7) Malfoy (2) Derrick (5 or 6) Bole (5 or 6)	Romania
1993-1994 (PA)	/	Wood captain (7) Angelina (5) Alicia (5) Fred (5) George (5) Harry (3) Katie (4) "Gryffindor hasn't won for seven years now" Oliver Wood, at the beginning of the year [off by one year, but apparently he's taking the cancellation of last year into account]	Flint (7 again) Malfoy (3) Derrick (6 or 7) Bole (6 or 7) Cedric Diggory (6) Cho Chang (4)	Romania
1994-1995 (GF)	Quidditch cancelled none/? At the Leaving Feast, the usual decorations of the color of the winning house were replaced by black to pay respects to Cedric.	(Wood joins Puddlemere United's Reserve Team)		Romania
1995-1996 (OP)	/?	Angelina captain (7) Ginny (4) Ron (5) Alicia (7) Fred banned after 1 game (7) George banned after 1 game (7) Harry banned after 1 game (5) Katie (6) Andrew Kirke (at least 2) Jack Sloper (at least 2)	Warrington (7) Miles Bletchley (at least 6) Adrian Pucey (at least 6) Malfoy (5) Crabbe (5) Goyle (5) Cho Chang (6)	Romania
1996-1997 (HBP)	?/?	Possible team: Ginny (5) Ron (6) Katie (7) Andrew Kirke (at least 3) Jack Sloper (at least 3) Harry (6) missing: one more Chaser	Possible team: Malfoy (6) Crabbe (6) Goyle (6) Cho Chang (7)	?

Look at the following chart a little more closely and you might be a bit surprised. Most of the Gryffindor players were actually very young when Harry came on board. Oliver Wood was only a fifth year when he became captain, and the rest of his team is even younger. Here's a chart showing the team in Harry's first year. Yes, Katie wss only 12 years old in that year... just a kid.

When Harry Joins the Team...

Player	Year	Age	Experience
Oliver Wood	5th	15 at the start of the year, unknown when he turned 16	3 years (he was captain last year too, which means he almost certainly must have played one more year besides)
Angelina Johnson	3rd	14 years old (born in October)	1 year (started in her 2nd year)
Alicia Spinnet	3rd	13-14 years old	1 year "only a reserve" (started in her 2nd year)
Fred Weasley	3rd	13 until spring (born April 1)	1 year (started in his 2nd year)
George Weasley	3rd	13 until spring (born April 1)	1 year (started in his 2nd year)
Katie Bell	2nd	12-13 years old	this has to be her first year

Conclusion:
When JKR wrote book one, she intended Charlie to have left seven years before, which was the last time that Gryffindor won the two Cups. Every quote from the books points that way. Subsequent books reinforce this. However, the WBD chat suggests that she doesn't really think of Bill and Charlie as being all that much older than Percy, Fred, George, Ron, and Ginny. She acknowledges a weakness for maths, and this is a clear example of exactly that. What JKR intended and what she wrote are two different things.

So how old are Bill and Charlie?
According to the books, Charlie left Hogwarts in June of 1984, seven years before Ron came. We'll go with Jo's statement that there are two years between Charlie and Bill, since we have nothing in the books to contradict that. Here's the timeline of the Weasley children, then, according to the books:

	Bill	Charlie	Percy	Fred & George	Ron	Ginny
1963	b.
1964
1965		b.
1966
1967
1968
1969
1970
1971
1972
1973
1974	1
1975	2
1976	3	1	b. Aug22
1977	4	2
1978	5	3		b. Apr1
1979	6	4
1980	7	5			b. Mar1
1981	June - leaves	6				b. Aug15
1982		7
1983		June - leaves
1984
1985
1986
1987			1
1988			2
1989			3	1
1990			4	2
1991			5	3	1
1992			6	4	2	1
1993			7	5	3	2
1994			June - leaves	6	4	3
1995				7	5	4
1996				May - leave	6	5
1997					7	6
1998					June - leaves	7
1999						June - leaves