29.53 days after the last one.
The last 8th phase.
My closest answer is 3.5 days but I'm not exactly sure.
around 3 days, sometimes a bit more
As of February 5th, 2010, the moon will enter the Last Quarter, and will enter the New Moon phase as of February 14th. So on February 13th, the moon will still be in the Last Quarter phase.
Full Moon -> Waxing gibbous phase -> First quarter phase -> Waxing crescent phase -> New moon -> Waning crescent phase -> Last quarter phase -> Wanning gibbous phase -> Full Moon
About 29.5 days.