(1) Where a trade or profession has been set up and commenced within the year of assessment, the computation of the profits or gains chargeable under Case I or II of Schedule D shall be made either on the full amount of the profits or gains arising in the year of assessment or according to the average of such period, not being greater than one year, as the case may require and as may be directed by the inspector.
(2) Any person chargeable with income tax in respect of the profits or gains of any trade or profession which has been set up and commenced within one year preceding the year of assessment shall be charged -
(a) if only one account was made up to a date within the year of assessment and that account was for a period of one year, on the full amount of the profits or gains of the year ending on that date,
(b) if -
(i) an account, other than an account to which paragraph (a) applies, was made up to a date in the year of assessment or more accounts than one were made up to dates i
…