The period of time when the Sun is near alignment with a lunar node, during which eclipses may take place. For solar eclipses, this time window of 31-37 days occurs every 173.3 days.
WARNING. Never look directly at the bright surface of the Sun without suitable eye protection as permanent eye damage may result. This applies at any time and especially during the partial phases of a solar eclipse. Refer to “How to observe the Sun safely”.