You have the option to define the text overlayed on the main window during simulation, by clicking Edit in the Simulation Settings dialog.

By default the date and time are displayed using the format specified in Control Panel, Regional Settings . You can specify the exact format to use by entering text into the text box. Most text will appear as entered, except that words prefixed with a or character act as keywords and are replaced with various values. The Date/Time and Extras buttons can be used to select and insert all possible keywords. The Colors button can be used to define the color of the Overlay Text.
The Font button brings up the standard Microsoft Windows font picker dialog box. Once the correct font, font style and point size have been selected, press Okay to return to the Overlay Text dialog box. The current font selection is shown next to the Font button, and during the TimeLiner simulation, all text on the overlay will be shown using this font.
Abbreviated weekday name
Full weekday name
Abbreviated month name
Full month name
Date and time representation appropriate for locale
Day of month as decimal number (01 - 31)
Hour in 24-hour format (00 - 23)
Hour in 12-hour format (01 - 12)
Day of year as decimal number (001 - 366)
Month as decimal number (01 - 12)
Minute as decimal number (00 - 59)
Current locale's A.M./P.M. indicator for 12-hour clock
Second as decimal number (00 - 59)
Week of year as decimal number, with Sunday as first day of week (00 - 53)
Weekday as decimal number (0 - 6; Sunday is 0)
Week of year as decimal number, with Monday as first day of week (00 - 53)
Date representation for current locale
Time representation for current locale
Year without century, as decimal number (00 - 99)
Year with century, as decimal number
Time-zone abbreviation; no characters if time zone is unknown
Time-zone name; no characters if time zone is unknown
Sets the overlay display text color to be red.
Sets the overlay display text color to be blue.
Sets the overlay display text color to be green.
Sets the overlay display text color to be white.
Sets the overlay display text color to be black.
Sets the overlay display text to any color specified using explicit rgb values between 0 and 255. For example, $RGB127,127,127$RGB sets the color to grey.
Adds the name of each currently active task to the overlay display text. Each task is displayed on a new line.
Days since start of first task in project (starting from 1)
Weeks since start of first task in project (starting from 1)
Type Ctrl+Enter to insert a newline into the overlay display text.
Percent sign