Gulika Kaal (also called Maandi) is an inauspicious daytime period ruled by Gulika, a sub-body of Saturn. Like Rahu Kaal, it is one of the eight equal day-parts and shifts with the weekday, sunrise and sunset.
Both are inauspicious eighth-parts of the day, but they fall on different parts for a given weekday and are ruled by different bodies — Gulika (a son of Saturn) versus Rahu. Gulika Kaal is generally regarded as slightly less severe.
For most new beginnings it is avoided. However, some traditions consider it acceptable for certain remedial or Saturn-related activities. It is best avoided for weddings, travel and new ventures.
For educational purposes. Astrological interpretations are traditional and not a substitute for professional advice.