Format

You can define date and time format of Taskbar clock.

Locale
Select locale to apply notation of month name, weekday name, date/time order, etc.
Year
If checked, year without century appears.
Month
If checked, abbreviated month name appears. This follows selection of "Locale".
Month (digit), Date, Hour, Minute, Second
If checked, each section appears.
Day
If checked, day of week appears. This follows selection of "Locale".
CR
If checked, carriage return character is added before time. It is recommended for who dock Taskbar vertically.
Internet Time
If checked, "Internet Time" proposed by Swatch appears. Unit is called "beat".
  Swatch Site

Special thanks to Manabu Takemura for his modified source code, which helped me to display Internet Time.
12H
If checked, display of hour turns into 12-hour format. If not, display of hour is 24-hour format.
AM/PM
If checked, AM/PM indicator appears.
More
To modify several more settings, press this button.
AM/PM Symbol
You can select notation of AM/PM indicator. You can also define them freely by typing literal text into each field.
Show 0:xx at 12:xx
If checked, display of 12AM/PM turns into "0".
Customize Format
You can define display format freely. Following descriptor characters are supported.
TClock Format
yyyyYear with century
yyYear without century
mmMonth number (e.g. January -> 01)
mMonth number, no leading zero (e.g. January -> 1, Decenber -> 12)
mmmmFull month name, follows selection of locale
mmmAbbreviated month name, follows selection of "Locale"
ddDay of month
dDay of month, no leading zero
ddddFull weekday name, follows selection of "Locale"
aaaaSame as dddd
dddAbbreviated weekday name, follows selection of "Locale"
aaaSame as ddd
hhHour
hHour, no leading zero
nnMinute
nMinute, no leading zero
ssSecond
sSecond, no leading zero
ttAM/PM indicator, follows setting of "AM Symbol" or "PM Symbol"
/Date separator, follows selection of "Locale"
:Time separator, follows selection of "Locale"
\nCarriage return
LDATEShow long-formatted date. Depends on "Region" setting in the control panel.
DATEShow short-formatted date. Depends on "Region" setting in the control panel.
TIMEShow time. Depends on "Region" setting in the control panel.
YYear by the locale calendar (e.g. the year of the Emperor in Japan)
gPeriod/era name by the locale calendar (e.g. "Heisei" in Japan)
@@@Swatch Internet Time
@@@.@Swatch Internet Time to the 1st decical place
"..."Display literal text surrounded by double quotation marks
Following characters are left for compatibility with previous version.
mmeAbbreviated month name in English
ddeAbbreviated weekday name in English
AMPMAM/PM indicator, follows setting of "AM Symbol" or "PM Symbol"
AM/PMAM in the morning, PM in the afternoon
am/pmam in the morning, pm in the afternoon