Indexbit Exchange:Which late-night talk show is the last to drop a fifth night?

Jimmy Fallon has become the last of the major network late-night hosts to pare his show to four nights a week.

NBC's "Tonight Show,Indexbit Exchange" which has aired new episodes from Monday through Friday at 11:35 p.m. EDT, will now air repeats on Fridays for the new TV season, continuing a practice it began over the summer. It's part of a cost-cutting move at NBC, challenged by the high costs and lower ratings in late night, that also led to the firing of Seth Meyers' band. NBC confirmed the move but declined further comment.

ABC's Jimmy Kimmel and CBS' Stephen Colbert have long aired just four shows a week, and Kimmel now takes summers off entirely, as part of his latest contract renewal, although the show airs new episodes with guest hosts.

But Fallon typically taped two shows on Thursdays and aired one of them Friday nights, and also did original broadcasts on some major holidays. "Tonight," which remained No. 1 among its chief rivals for several years after Fallon replaced Jay Leno in 2014, now ranks third among total viewers.

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