Every Sunday morning for the past 50 years, Mr Nelson, 76, of Main Street, Cononley, has climbed 13 rungs up a ladder in the institute’s clock tower to manually wind the clock.
But those days have now finished after an electric mechanism was installed.
Mr Nelson took on the job in 1963 and in the early days received payment for his efforts.
Mr Nelson said it only took 15 minutes out of his day and needed doing just once a week.
He wound the clock 30 times for it to strike and 46 more times for the bell to chime.
He said the clock has been “very, very good” at keeping the time over the past 50 years.
Mr Nelson was very dedicated but admitted: “I won’t miss it, especially climbing up 13 rungs on a ladder to get into the tower.”
Parish clerk Stephanie Wheelhouse said it had cost £3,500 to convert the clock.