from the label.dll docs:

Text Escape Sequences
---------------------

To include dynamic text in labels, such as system information, you can use
escape sequences mixed in with normal text in labels. Escapes sequences
consist of a data source names and any necessary parameters and possibly
one or more modifier functions all enclosed in square brackets:

LabelText "Just some test... [modifier(dataSource(parameter))]"
ClockLabelText "The time is: [time]"
QuoteLabelText "Quote of the Day: [trim(randomLine('C:\quotes.txt'))]"
SysLabelText "CPU: [cpu], RAM: [memInUse]"

<snip>

iTime
Current time as Swatch internet time (beats).