Timezone is wrong
Note: This tip applies only to iPhone users.
If Timezone looks wrong in the graph on Timeline Pane, you can try the following to reset Timezone:
1) In the "Settings" app on your phone: tap "General" >"Date & Time". Change to a different timezone.
2) Open the Cardiogram app.
3) Go back to your settings, change timezone back to the correct one you desire.
4) Re-open the Cardiogram app.