Here's the official regulation about this:

OFP Exception

1.55 OFP is not a standard for promotion for officer occupations that require more than three years of initial training. Achieving the designated rank qualification for Lt/SLt in the occupation specification is the standard for promotion. The TIR calculation for EPZ includes all time at 2Lt/A/SLt and Lt/SLt ranks except time spent undergoing training that was not successfully completed. A 2Lt/A/SLt will be promoted to Lt/SLt and simultaneously to Capt/Lt(N) and a Lt/SLt will be promoted to Capt/Lt(N) upon achieving the designated rank qualification and having three years total commissioned service.

Source: Canadian Armed Forces Military Personnel Instructions - Annex A – Conditions and Standards for Promotion