From the Super Mario Wiki, the Mario encyclopedia

First appearance

Dr. Mario World (2019)

Effect on player

Adds extra seconds prior to starting a stage

Time+ is a bonus item in Dr. Mario World. Appearing only in the special timed stages (eg: 1A, 1B, 1C and so on), they grant players additional seconds rather than extra capsules (as the timed stages have infinite capsules), replacing Capsule+'s functionality. Like Capsule+ items, the first one is given for free while subsequent uses of it require 10 diamonds to be purchased.