I think I challenge that statement. I manage to pick a Date Header Format YYYY-MM-DD and a Timestamp Format HH:MM:SS, if I pick English (United Kingdom) or Swedish (Sweden) for my Language option in Blogger’s Settings / Formatting subtab. There does arguably not seem to be any apparent way of emitting time zones (whether it be +01:00 or something else due to daylight savings time, in my case of Central European Time), but you can choose a Time Zone setting of [UTC +00:00] Coordinated Universal Time, and use the YYYY-MM-DDTHH:MM:SSZ format for the microformat reading.

Certainly not the least bit pretty, certainly not what we want, but I think I’ll go down this route for myself, anyway. We can always wail at Blogger, asking for a few more template tag fields, too, of course — exposing year, zeropadded month, day, hour, minute and time zone hour / minute offsets should be a very simple addition to their nice template engine, as soon as someone in a deciding role gives a “go” to the right in-house developer.

But until then, there are kludges, at least.