_date - UDM Built-in Variable
The _date built-in variable displays the current date in the format appropriate for the system's locale.
_date has several additional variable attributes:
day resolves to the day of the week.
month resolves to the current month.
dd resolves to a two-digit day of the month.
ddd resolves to the Julian day.
mm resolves to the two-digit month of the year.
yy prints the two-digit year.
ww resolves to the two-digit current week of the year.
yyyy resolves to the four-digit year.
Note
The value of ww is zero-based, not one based. That is, the first week of the year is 0, the second week is 1, the third week is 2, and so on.
The _date variable can be referenced only in your scripts and cannot be set.