Avidyne IFD540 Pilot's Manual page 115

Trip Timer
The "Trip Timer" provides an option to start from either IFD power
on or from take-off (the active selection will be displayed in a blue
background), along with a Reset capability.
This timer will automatically reset with each power cycle or take-
off, depending on which selection was made.
Departure Time
The "Departure Time" provides an option to start from either IFD
power on or from take-off (the active selection will be displayed in
a blue background) and indicates the clock time (Zulu or Local)
associated with the active blue selection.
The selection of Zulu or Local is automatic and dependent on the
"Time Format" choice made on the "User Options" LSK of the
SETUP tab on the AUX page.
Custom Timer
Up to 10 custom timers can be created by inserting a new timer
below the Departure Time slot.
Twist the bottom right IFD knob to create an insert cursor at the
bottom of the current timers list and push in the knob to create the
new custom timer.
Typical uses include creating timers for 50hr and 100hr
inspections, Annual inspections, Bi-annual air data system
checks, BFRs, etc.
The user may choose from three types: an event-based timer, a
1-time event timer, or a periodic timer. Depending on which type
was selected (indicated by a blue background), different types of
date and time entries can be made and for the periodic selection,
a count-down of remaining time is also displayed.
The custom timer can be named by selecting the title field using
the bottom right IFD knob and pushing it in to get into edit mode.
Then twist the inner and outer rings as required to create a
custom name for the timer. When finished naming the timer,
push the IFD knob to exit the edit mode.
AUX Pages 4-7