This field toggles when cron-shelve will execute using jenkins cron functionality
This field follows the syntax of cron

[MINUTE] [HOUR] [DOM] [MONTH] [DOW]

H not to be confused with hours is used to derive a hash from a project name.
The hash is used to create a unique and but consistant time signature. This
ensures jobs do not execute at the same exact time.
examples:
# every fifteen minutes (perhaps at :07, :22, :37, :52)
H/15 * * * *

# every ten minutes in the first half of every hour (three times, perhaps at :04, :14, :24)
H(0-29)/10 * * * *

# once every two hours every weekday (perhaps at 10:38 AM, 12:38 PM, 2:38 PM, 4:38 PM)
H 9-16/2 * * 1-5

# once a day on the 1st and 15th of every month except December
H H 1,15 1-11 *