Most YMCAs are a good bet for camps with extended day options both in the morning and the evening. Facilities such as Greenwich, Darien, New Canaan, and Fairfield run preschool and school-aged general day camps as well specialized sports camps. Hours vary by camp, but generally fall around 9 am - 3 pm, with extended hours to 5:30 or 6pm. (Often school-age camps are held at separate facilities including recreational centers, parks, or elementary schools so be sure to check the specific location where the camp is being held.)
 
Central Connecticut YMCA (Bridgeport), 850 Park Avenue, 203-334-5551
Central Connecticut YMCA (Fairfield), 841 Old Post Road, 203-255-2834
Darien YMCA, 2420 Post Road, 203-655-8228
Greenwich YMCA, 50 Putnam Avenue, 203-869-1630
New Canaan YMCA, 564 South Avenue, 203-966-4528
Westport/Weston YMCA, 14 Allen Raymond Lane, 203-226-8981
Western Regional YMCA (Bethel), 57 Grassy Plain Street, 203-744-4890
Western Regional YMCA (Brookfield), 2 Huckleberry Hill Rd, 203-775-4444
Western Regional YMCA (Danbury), 293 Main Street, 203-794-1413

Italian Center Day Camp, Stamford
The Italian Center Club is a private club in Stamford that operates a full-day camp for kids in grades K-6 (as well as a half-day camp for preschoolers) that is available for members and non-members alike. Typical activities include swimming, dancing, gymnastics, and arts and crafts. Camp runs from 9 am to 4 pm, with extended hours available from 8 am to 5 pm.

1620 Newfield Avenue, 203-322-6941

Stamford JCC,  Stamford
Just down the road from the Italian Center, the Stamford JCC offers Camp O-la-mi, a full day camp for kids in kindergarten to eighth grade (a half-day camp that may be extended until 4 pm is available for preschoolers). Campers enjoy a fun-filled schedule, complete with specialties including art, sports, instructional swim, dance, and more. The middle school program allows kids to participate in a community service project as well. Camp runs from 9 am to 4 pm, with extended hours available from 7:30 am to 6 pm. Camp is open to the community as well as members.

1035 Newfield Avenue, 203-322-7900

Long Ridge Camp, Stamford
Long Ridge Camp is one of the few that extends a full day option to preschoolers as young as 3, as well as to student all the way up to eighth grade. We hear raves about this traditional camp in the woods of North Stamford, and especially nice perk is that they offer bus transportation to and from camp for all campers. Regular hours are 9:30 am to 4:00pm, with extended hours available from 8:15 am to 5:30 pm.

478 Erskine Road, 203-322-0253

Camp Playland, New Canaan
The motto of this beloved camp in New Canaan is "the day camp with the away camp atmosphere," and it shows. Already in its 59th year, Camp Playland offers swimming, athletics (soccer, baseball, tennis, golf, lacrosse, basketball, street hockey, football, and more), and arts (dance, drama, music, and crafts), as well as special theme days and events all summer long. Regular hours at the camp are 9:30 am to 4 pm, with extended hours available until 5 pm. Rates include bus transportation to and from camp. (There is a sister camp in Redding with slightly more affordable rates).

802 Ponus Ridge, 203-966-2937

Camp Aspetuck, Weston
Camp Aspetuck is a rustic Girl Scout camp available to girls (Scouts and non-Scouts alike) in grades 1-8. Camp Aspetuck is no frills, but for $495 per two week session (or $270 per one week session), it's a bargain. My daughter attended last year, and this was hands-down her most memorable camp experience to date. Girls learn traditional Scouting songs, participate in arts and crafts, swimming, and other games and adventures on the wooded property. Regular hours are 9 am to 4 pm, but a breakfast bunch is available beginning at 7 am. Most students commute to camp via bus, which is included in the camp fees, and depending on the schedule for your town, may stretch your camper's day even longer. (Camp Aspetuck is having an open house on May 3rd if you want to learn more about the program.)

88 Old Easton Turnpike, 203-226-6536