Assessment time limits and exclusion rules govern completion periods for reassessment, recomputation, transfer pricing, and effect-giving orders. Time limits are prescribed for completion of assessment, reassessment, recomputation, fresh assessment, and orders giving effect to appellate or court directions. Most listed orders must be passed within one year from the relevant reference point, while some effect-giving orders allow six months, extendable to nine months, and certain modification orders must be completed within two months. The provision also excludes specified periods from limitation, extends time where transfer pricing references are made, and deems additional time in cases where the remaining period becomes very short after exclusions.