That obviously depends on how much of the hour the light is turned on. Neither of them uses ANY energy when it's turned off.
The difference is (60 - 55) = 5 watts = 5 joules per second.
If the light is on for the entire hour, then the difference in energy is
(5 joule/second) x (3,600sec/hr) = 18,000 joules/hour.
Putting it in a more familiar unit . . .
(5 watts) x (1 hour) = 5 watt-hours = 0.005 Kilowatt-hour.
If your utility company charges you 25¢ per kilowatt-hour (a very high rate), then the more energy-efficient light bulb saves you (0.005) x (25¢) = 1/8 penny per hour of operation.
