Calculation sequence
How this method is divided
- 01
The eclipse calculation returns a strictly previous and strictly next peak. Events are penumbral, partial, or total. The nearest result is selected by elapsed time, without treating a larger or total eclipse as automatically nearer.
- 02
Penumbral, umbral, and totality contacts fall symmetrically around the peak by their available semi-durations. Phases that do not occur are absent. Global contacts are compared with the Moon's local altitude to find which stages are above an observer's ideal horizon.
Working sheets
Two focused guides
Method selection
Where this method fits
- Use the finder to bracket one exact instant with the previous and next global eclipse peaks.
- Use the eclipse visibility checker to compare all contacts and the intervals between them with the observer's ideal horizon. The Moon's visible upper limb sets the horizon crossing; hills, buildings and local weather can shorten an actual view.
- Umbral obscuration is covered disc area and is different from the catalogue quantity called umbral magnitude.
Put the method to work
Use the working calculation
Evaluate another exact instant with the calculator described here, or return to the overview for the shared time conventions and supported era.