Dayal was born Manish Patel in Orangeburg, South Carolina, to parents from Gujarat, India, Hema and Sudhir Patel. He uses his grandfather's first name, "Dayal", as his stage surname. He started his career appearing in national commercials for McDonalds, Windows, Nintendo, and Domino's Pizza. In 2008, he played the lead in The New Group's twice-extended off-Broadway show Rafta, Rafta.... He played a small role in Jerry Bruckheimer's The Sorcerer's Apprentice and Paula van der Oest's Domino Effect. After guest starring on CSI: Las Vegas on CBS, Dayal went on to play Hal, a code-breaking computer analyst, on the AMC series, Rubicon. Dayal also starred in the romantic comedy Walkaway, which explores love and culture set in New York. In 2010 and 2011, he played Ravi, the smug A-team leader on Outsourced, a comedy series from NBC. He also played Raj Kher, an alternative college student recovering from cancer, in the third and fourth seasons of The CW's 90210. He starred as Hassan Kadam in The Hundred Foot Journey (2014).