The Telegraph reports that Michael Gove has declared that he wants to cut the length of school holidays in order to improve standards. I’ve plotted a graph of the number of hours that teachers spend teaching per year (from OECD TALIS data) against their average PISA scores. Draw your own conclusions:
You can download my data here.
Just had this contrasting but fascinating graph sent to me by @par_izglitibu

Teaching days per year versus Avg PISA maths score
Perfectly understandable, days are shorter. Also see bokhove.net/2013/04/19/longer-schooldays/