Dear Vasanth,
The concept of 180 days is important for the purpose of Depreciation Calculation.
- If a new asset is bought and put use for less than 180 days in a financial year (ie., acquisition on or after Oct1) , only half the rate of actual depreciation, you can charge.
- If a new asset is bought and put use for more than 180 days in a financial year (ie., acquisition before Oct1), full rate of Depreciation you can charge.
- The applicability of the date '3rd October' will come in the case of Leap Year.
But, usually this date is considered that much important only in the exam point of view.