#work_shift__shift__duty_period  the time period during which you are at work
  supertype:  hours  a period of time assigned for work; "they work long hours"
  part of:  workday
  subtype:  spell__go__tour__turn  a time for working (after which you will be relieved by someone else); "it's my go"; "a spell of work"
  subtype:  trick.work_shift  a period of work or duty
  subtype:  watch.work_shift  a period of time (4 or 2 hours) during which some of a ship's crew are on duty
     subtype:  dogwatch  either of two short watches: from 4-6 pm or 6-8 pm
     subtype:  graveyard_watch__graveyardwatch__middle_watch__midwatch__night_watch__nightwatch  a watch during the night (as from midnight to 8 a.m.)
  subtype:  day_shift__dayshift  the work shift during the day (as 8 a.m. to 4 p.m.)
  subtype:  swing_shift__swingshift__evening_shift__eveningshift  the work shift during the evening (as 4 p.m. to midnight)
  subtype:  graveyard_shift__graveyardshift__night_shift__nightshift  the work shift during the night (as midnight to 8 a.m.)
  subtype:  split_shift__splitshift  a working shift divided into two periods of time with several hours in between

No statement uses or specializes work_shift; click here to add one.