Data truncated: Incorrect TimeStamp

Hi,

I'm using Mysql to insert 12 new rows with an interval of 28 days I've tried date_add function. But, an error appears which reads as " Incorrect datetime value :Time stamp truncated" . insert ignore wouldn't iterate for 12 times. Kindly, help me solve this issue:  

create procedure MonthlyDeferredRevenue()
BEGIN
Set @v_max1 = 13;
Set @v_counter1 = 1;
Set @v_days =28;

start transaction;

while @v_counter1 < @v_max1 do

Set @v_days = @v_days * @v_counter1;

INSERT INTO cb_sf_masterdata_interim (OpportunityCloseDate)

SELECT  DATE_ADD(OpportunityCloseDate, Interval @v_days day)

FROM cb_sf_masterdata_temp where adjustedrevenue >= 2500 ;

SET @v_counter1 = @v_counter1 + 1;
end while;

commit;
end;