What is Rāhu kāla, and should I avoid starting things in it?

it is a daily window of about 1½ hours, one-eighth of daytime, traditionally avoided for new beginnings — not for routine work.

The time from local sunrise to sunset is split into eight equal parts, and one part each weekday is assigned to Rāhu: the 8th on Sunday, 2nd on Monday, 7th on Tuesday, 5th on Wednesday, 6th on Thursday, 4th on Friday and 3rd on Saturday. With a 6 am sunrise and 6 pm sunset, Monday's Rāhu kāla is about 7:30–9:00 and Sunday's 4:30–6:00. Because sunrise changes with season and city, the exact time changes daily.

The practice is strongest in South India, where people avoid starting a journey, signing a deal, or beginning a new venture in it. Ongoing work, office hours, studies, meals and prayers continue normally — in fact some temples hold special Durgā worship during Rāhu kāla.

If an important event must fall in it, simply pray to Gaṇeśa and proceed calmly.

Source: South Indian pañcāṅga practice · 1/8 of daytime, varies daily

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