SugarCube 2.18 Problem with temp variables and for

Hello.
SugarCube 2.18 Twine 2.1.3
I am making things like this:

$$time =
<<for _time = 0; _time <= $MAX_TIME; _time++>>
	<<if _time != $time>>
	[[_time->Debug][$time = _time]]
	<<else>>_time<</if>>
<</for>><br>

for testing game. And problem is in [[_time->Debug][$time = _time]]. How you can see $time = _time, but instead of numbers there are undefined in $time. I understand why, but I need numbers. If _time = 1 then [[_time->Debug][$time = 1]]. How I can convert variable in constant? I tried $time = "_time" and $time = `_time` but it doesn't work.
Thank you.