Formula Help: Return 0 if the fields are blank, otherwise run formula

[Noelie2000 (Noel Pusey)]

@JCorrell

IF(AND({H1}, {H2}),
  ABS(TIMEVALUE("1/1/1 " & {Dep D2}) - TIMEVALUE("1/1/1 " & {Arr D1 (Rtn)})) * 24
, 0)

That just totally made me rethink the way I calculated the columns; reduced the process by half.

Many thanks.