partial time stamp query

I am trying to write a query that grabs one particular day from a timestamp column. The data are ordered in 15 minute chunks like this:

2010-07-07 12:45:00
2010-07-07 13:00:00
2010-07-07 13:15:00
2010-07-07 13:30:00
etc…

If I wanted all records from july 7th 2010, I would expect 4 x 24 = 96 records per day.

I have tried the '=' operator, like this

WHERE derived_tsoil_fifteen_min_stacked.time2 = '2010-07-07*'

but that grabs nothing, and using the '~' operator grabs everything with a 2010 or 07 in it… in other words all days from July of 2010.

Any suggestions would be much appreciated.