Loop Syntax Correction

Hello. I am having a bit of trouble with this for-loop, a syntax error and would love an extra pair of eyes on this,

I basically have a 'Hire Date' field, and I would like to generate a concatenated list of the number of full years since the 'Hire Date' and today. For example: 

hire date:=12/22/2012;
tdy:=12/14/2022;
response:= [0,1,2,3,4,5,6,7,8,9]

Please note the zero, and also note the 10 is missing since the anniversary date has not passed the 10 year mark. 

I know I am close, but I am getting a syntax error if someone could please assist.

let currentDate := now();
let hireDate := this.'Hire Date';

let years := (currentDate - hireDate) / 365;

let yearsString := "";

for i in (let i := 0; i < years; i++) do
  let year := hireDate + (i * 365);
  yearsString := yearsString + year + ", ";
end;

yearsString