Messages for ::tcl::clock in uk (Ukraine) locale (file is wrong.
DAYS_OF_WEEK_ABBREV - no first uppercase letter.
DAYS_OF_WEEK_FULL - no first uppercase letter.
MONTHS_ABBREV - no first uppercase letter, different number of letters for the month abbreviations.
MONTHS_FULL -  no first uppercase letter, invalid use of case for month names.
DATE_FORMAT, DATE_TIME_FORMAT - wrong date format.

Correct message file is:
----------------------------------------------------------
namespace eval ::tcl::clock {
    ::msgcat::mcset uk DAYS_OF_WEEK_ABBREV [list \
        \
        \
        \
        \
        \
        \

    ::msgcat::mcset uk DAYS_OF_WEEK_FULL [list \
        \
        \
        \
        \
        \
        \

    ::msgcat::mcset uk MONTHS_ABBREV [list \
        \
        \
        \
        \
        \
        \
        \
        \
        \
        \
        \
        \
        ""]
    ::msgcat::mcset uk MONTHS_FULL [list \
        \
        \
        \
        \
        \
        \
        \
        \
        \
        \
        \
        \
        ""]
    ::msgcat::mcset uk BCE
    ::msgcat::mcset uk CE
    ::msgcat::mcset uk DATE_FORMAT "%d.%m.%Y"
    ::msgcat::mcset uk TIME_FORMAT "%k:%M:%S"
    ::msgcat::mcset uk DATE_TIME_FORMAT "%d.%m.%Y %k:%M:%S %z"
}