The Prepositions of Time

http://www.englishexercises.org/makeagame/viewgame.asp?id=2988

http://perso.wanadoo.es/autoenglish/gr.time.p.htm

http://www.ego4u.com/en/cram-up/grammar/prepositions/exercises?02

http://www.perfect-english-grammar.com/time-prepositions-exercise-2.html