All kidding aside, though, I think I'd average 8 hours over the span of 2 to 3 weeks to complete a 1/48 single engine aircraft.  I built a couple of Mustangs last summer (which I had originally started in 2010, with an eye towards finishing for my club's December meeting that year, theme was "Ponies") and finished them in that timeframe, in about 8 hours.  Apart from having a lot of kits in progress at once, I have to account for steps in which I'm waiting for something to cure, like glued joints or coats of paint.  I wait 24 hours, for example, between applying a gloss coat for decals and actually applying them.  That tends to stretch the schedule out.  And on that Fiat G50 I mentioned, I've redone the paint twice, because I wasn't happy with the results.  That pushed completion back even further.