If you’re looking around your office this morning and wondering where everyone is, Microsoft might be to blame.

Outlook 2010 users who’ve added national holidays to their calendar may notice that Microsoft is declaring today as the Spring Bank Holiday. That, of course, isn’t the case: the Government put the Spring Bank Holiday back until next week, and added another day off for the Jubilee for good measure, to create a four-day weekend.

Unfortunately, it seems Microsoft didn’t get the memo. Or, at least, it didn’t bother to push an update to its bank holiday schedules, which were correct at the time Office 2010 was released.

It seems we’re not the only ones being plunged into potential confusion. According to this incredibly detailed blog post at Meteor IT — which also provides instructions on how to locate and correct the Outlook calendar – at least 23 countries are suffering from incorrect holiday dates.

I suspect The British Chambers of Commerce — or some other jobsworth society — is already working out how much this is likely to cost the British economy, rounded up to the nearest £10 billion.

In the meantime, I’m off to enjoy an unexpected Bank Holiday in the sun. Toodle pip.