Chanting slokas at any time is good if you do it well with total devotion. A solar eclipse is a monthly phenomenon when Sun and Moon come at the same longitude and latitude which happens somewhere in the world on every New Moon day and a Lunar eclipse is on a Full Moon day when Sun and Moon are 180 degrees apart. There is nothing to be frightened about it. Watching the Sun with the naked eye is dangerous and you must use dark glasses to watch it if you must.