TimePicker: make pickerMax closer to midnight in case clickableIncrement < 15 min.
Refs #18200.

(cherry picked from commit 417cdbf4b0181d4f65d36aeefaac36971b457d43)
Number format patterns do not have locale-specific decimal separators.
This was causing issues in locales where the decimal separator is not a period.

Fixes #18260, refs #17955.

(cherry picked from commit 00568aa6e4f319e1440918e6bd79e36bbbc7046e)