Epic Time Tracking makes use of the estimation of an epic to calculate the remaining time across it's child issues. However, epic estimations are not required so it's possible to have an epic without it's own estimation. When this happens Epic Time Tracking calculates it's own original estimate. This is done by taking the estimate of all child issues of the epic and summing them up.
Not that the estimation calucated by Epic Time Tracking is only used by the Epic Time Tracking panel. The estimations of the epic will not be changed.
Automatic Epic Estimation Example
You have an Epic which has 3 child issues. The epic has no estimation.
|Issue 1||Issue 2||Issue 3|
|Original Estimate||3h 30m||4h 30m||7h|
Newly Calculated Epic Estimate = 3h 30m + 4h 30m + 7h = 15h
Total Logged Time = 10h
Remaining under Epic = 15h - 10h = 5h