show decisecond when timer is at one second

[rulezyx]

Hello,

usually I write something like %.1f instead of %d to get it to show one decimalpoint.

But I want to make it so that it only turns to decimalpoint when the timer is at one (1) second.

so 3, 2, 1 ,0.9, 0.8. 0.7 etc.

Is there a simple solution to make this happen?

Thank you.