In California, it's as follows:
EMT-1 (Basic ) - 114 hours total with 104 hours of classroom/skills and 10 hours of either field ride-along or hospital clinical.
EMT-2 (Intermediate) - This level is only used in rural counties in the state. 306 hours total with 210 hours of classroom/skills and 96 hours of combined field ride-along and hospital clinical.
Paramedic - 1,032 hours total with 320 hours of classroom/skills, 480 hours of field ride-along and 160 hours of hospital clinical.
The number of days/months to complete the class varies a lot, particularly at the Basic level. Most community colleges make it a full semester or quarter class depending on their schedule. The program I did was a condensed class that was 5 weeks long: 6 hours a night, 4 nights a week.
California will be changing to the the National Registry in 2006 for Basic and may be eliminating Intermediate altogether. National Registry is already used for Paramedic.