d1
A number specifying the day of the month
d2
A number specifying the month of the year
d3
A number specifying the year (either four digits or the last two
digits of the year)
t1
A number specifying the hour of the day
t2
A number specifying minutes past the hour
t3
A number specifying seconds past the minute
If you precede any of these values with a plus sign (+) or a
minus sign (-), you will change the corresponding current value
by adding to or subtracting from it the value following the + or
-.