I think you might be referring to the weekend travel assistance, ref
CBI 209.31:
209.31 - REIMBURSEMENT FOR WEEKEND TRAVEL WHILE ON TEMPORARY DUTY
209.31(1) (Entitlement) Subject to paragraph (3), if authorized by their commanding officer to travel on a weekend, an officer or non-commissioned member who is on temporary duty in Canada away from their base or other unit or element in Canada is entitled to be reimbursed for travelling expenses to and from their normal place of duty or the place where their dependants are residing, except if any of the following circumstances exist:
a.the member is on temporary duty for the purpose of attending a course of training or instruction; or
b.after completion of the travel, there are fewer than three days of actual duty remaining at the temporary duty location.
209.31(2) (Reimbursement when performing tasks outside of normal duties) If authorized by their commanding officer to travel on a weekend, an officer or non-commissioned member who is on temporary duty in Canada away from their base or other unit or element in Canada for the purpose of performing tasks that are outside of their normal duties is entitled to be reimbursed once during each 30-day period of absence for travelling expenses to and from their normal place of duty or the place where their dependants are residing, if the following circumstances exist:
a.before beginning the travel, the member has served at least eight days of actual duty at the temporary duty location;
b.after completion of the travel, there are at least eight days of actual duty remaining at the temporary duty location; and
c.the member is a member of
i.the Regular Force,
ii.the Reserve Force on Class "C" Reserve Service, or
iii.the Reserve Force on Class "B" Reserve Service who, while on callout, is required to remain on callout and to perform tasks that are outside of their normal duties.
209.31(3) (Rate of reimbursement)The officer or non-commissioned member shall be reimbursed the expenses set out in the Canadian Forces Temporary Duty Travel Instruction, except that a member who is performing only tasks that are part of their normal duties shall not be reimbursed an amount that exceeds the cost of maintaining the member at the temporary duty location over the weekend.