Java Program that accepts input and meanwhile runs a timer

Java Program that accepts input and meanwhile runs a timer

I want to make a small java program that does the following: When it
starts running, a timer of 00:00 starts as well at the same time. Then,
the program asks the user for a user input (only "*" can be given) and
when it's inserted, it prints the very next number that has 0 in its last
digit of the timer. Example: program runs, timer as well, user gives *,
meanwhile, before it is inserted (by enter), timer continues to run and
when it is inserted, the timer is at 00:35 for example, and at 00:40 it
prints 00:40. Continues to run.. is at 01:32, gets insert, prints 01:40 at
that time, etc. Kinda confusing huh? :)
I don't know how to accomplish this, what should I read? Thanks a lot