assessee is firm. Its accounting year for assessment year presently under consideration ended on Diwali 1979. 2. ITO granted depreciation to assessee on its buses at rate of 30 per cent. 3. assessee challenged above order of ITO before Commissioner (Appeals) and claimed before him that depreciation on buses at rate of 40 per cent be granted to assessee in terms of amendment to item No. 9 of Group D forming part of Part I of Appendix I to Income-tax Rules, 1962 ('the Rules') by Notification S.O. 562(E), dated 24-7-1980, which came into force 'at once'. above plea of assessee was accepted by Commissioner (Appeals). While granting said relief to assessee, Commissioner (Appeals) made, inter alia, following observations: " manner in which notification has been inducted is unfortunate. Normally, in income-tax cases, changes are made with effect from particular date. Ordinarily, date is 1st April of particular year, indicating that new provision would be effective with reference to assessment year commencing on that date. In certain contingencies, provisions are made operative with effect from date on which event takes place. In that case also, ordinarily, particular date is mentioned intention made clear and date has some logic, e.g., first day of first month, say, 1st June or 1st October or 1st January. In this case, notice is dated 24-7-1980 and it comes into effect 'at once'. It appears to be quite odd that depreciation should be given at rate of 40 per cent on assets acquired after that date or put into use after that date or with reference to user of old pre-existing assets after that date. interpretation of notification in this regard is lawyer's paradise. One of constructions also might be that depreciation should be at rate of 40 per cent in assessments made after that date. appellant has produced copy of order of Tribunal, Hyderabad Bench 'A', in case of South India Road Transport v. ITO [1983] 4 ITD 176 to effect that enhanced depreciation at rate of 40 per cent would be applicable to proceedings for assessment year 1980-81. In view of intriguing import of impugned notification, it would be appropriate to abide by interpretation placed by Tribunal. Accordingly, ITO is directed to allow depreciation at rate of 40 per cent on lorries. Other grounds of appeal are not pressed. " 4. department challenges correctness of aforesaid direction of Commissioner (Appeals). 5. On behalf of assessee, reliance is placed on order of Commissioner (Appeals) and on following decision of Tribunal---South India Road Transport v. ITO [1983] 4 ITD 176 (Hyd.) and Rayalaseema Passenger & Goods Transports (P.) Ltd. v. IAC [1984] 7 ITD 111 (Mad.). 6. question in controversy before us would, in our opinion, turn on fact whether amendment in depreciation table is procedural in nature or is it amendment of substantive law. Section 32 of Income-tax Act, 1961 ('the Act'), provides for depreciation at rates as may be prescribed. Rule 5 of Rules, which has been formulated in pursuance of provisions of section 32, stipulates, inter alia, as follows: " Subject to provisions of sub-rules (2) and (3), allowance under clause (i) or clause (ii) of sub-section (1) of section 32 in respect of depreciation of buildings, machinery, plant or furniture . . . shall be calculated at percentages specified in second column of Table in Part I of Appendix I . . ." rates of depreciation mentioned in Appendix I of Part I are this part of rule 5 and thereby they form part of section 32(1) itself. Appendix I of Part I is, therefore, part of substantive law and it is not procedural in its nature. 7. Where there is amendment of substantive law, it is normally not retrospective unless amending Act itself makes it retrospective as in case, for example, sub-section (1A) of section 80J of Act introduced by Finance (No. 2) Act, 1980. In present case, amendment to item No. 9 in Group D in Appendix I of Part I was made by Notification S.O. 562(E), dated 24-7-1980 'at once'. interpretation of phrase 'at once' in context of aforesaid notification can only mean, according to us, with effect from 24-7- 1980. It is impossible to interpret phrase 'at once' as meaning with effect from 1-4-1980, particularly when order, which is to come into effect 'at once', is dated 24-7-1980. This being so, it is not possible for us to hold that amendment in question was part of substantive law as it obtained on 1-4- 1980. It is not first amendment of this type, which has come into effect from odd date in middle of financial year. fourth proviso to section 10(2)(vii) of Indian Income-tax Act, 1922 was inserted by Income-tax (Amendment) Act, 1946 ('the Amendment Act'), with effect from 4-5-1946. department had in that case contended that said proviso would apply to assessment for assessment year 1946-47. above contention was negatived by Bombay High Court, which held that fourth proviso to section 10(2)(vii) did not apply to assessment for assessment year 1946- 47 as said proviso was not in force on 1-4-1946 and that liability of company had to be determined as on 1-4-1946, when Finance Act, 1946 came into force. above finding of Bombay High Court was approved by their Lordships of Hon'ble Supreme Court, who pointed out, inter alia, that fourth proviso to section 10(2)(vii), inserted by Amendment Act, which came into force in May 1946, was not retrospective and was not in force on 1-4- 1946 and, therefore, did not apply to assessment for assessment year 1946-47. above ratio of aforementioned decision of Hon'ble Supreme Court would, in our opinion, squarely cover facts of present case and based on above ratio, we have no alternative but to hold that amendment to substantive law, which was brought into effect from 24-7- 1980, could not be made applicable to assessment for assessment year 1980-81, as assessment for that year would be governed by law as it obtained on 1-4-1980. When we hold as above, we must not be understood to imply that no amendment to substantive law can be retrospective. There can be such retrospective amendment of substantive law, as has been noted by us earlier, but point to be stressed is that unless wordings of amending c t themselves make it clear that amendment was being made with retrospective effect, amendment would not be retrospective but would be only prospective. 8. In South India Road Transport's case, our brothers had noted scheme of depreciation to be granted to assessee and had made, inter alia, following observations: ". . . In other words, scheme of depreciation is not with reference to date of acquisition but with reference to use during accounting year ...." [Emphasis supplied] We are in respectful agreement with above observations of our learned brothers. Applying above principle to facts of present case, we find that there is no user of machinery in question in accounting period corresponding to assessment year 1980-81 and, therefore, question of granting depreciation on asset in accordance with amendment brought into effect on 24-7-1980 would not arise. 9. significance of words 'at once' is unambiguous in context in which these words have been used in amendment referred to above, namely, that with effect from 24-7-1980, buses and trucks, etc., would be eligible f o r depreciation at rate of 40 per cent irrespective of date of their acquisition. Even if trucks had been acquired earlier and were then entitled for depreciation at rate of 30 per cent, depreciation on them after 24-7-1980 would be at rate of 40 per cent. Trucks and buses, which will be used on and after 24-7-1980, would be eligible for consideration with regard to their depreciation in assessment year 1981-82 only. As on 1-4-1981, law with regard to depreciation would be as was introduced with effect from 24-7- 1980. We visualize no difficulty in giving effect to above plain meaning of amended appendix. 10. There is reference in case of South India Road Transport to decision of Supreme Court in case of Mathra Parshad & Sons v. State of Punjab [1962] 13 STC 180. In that case, certain exemption with regard to some sales was granted on 27-9-1954. Their Lordships of Supreme Court said that said exemption would also be applicable even in respect of sales made since 1-4-1954 to 26-9-1954. If above ratio be applied to facts of present case, all that can be said is that amended rate of depreciation on trucks would apply not only with regard to trucks used from 24-7-1980, but also with regard to trucks used with effect from 1-4-1980. In income-tax, assessment is made on income of previous year and naturally, therefore, depreciation is to be granted on basis of user in previous year. previous year in present case, as noted earlier, had ended on Diwali 1979 and as on that date, rate of depreciation was 30 per cent, rate of 40 per cent could not be read into rule as on Diwali 1979. 11. In case of Rayalaseema Passenger & Goods Transports (P.) Ltd., it has been observed, inter alia, as follows: ". . . Board expressly provided that it [i.e., amendment] will take effect from 24-7-1980 shows that they wanted to apply it to all assessments pending on 24-7-1980. So amended rules apply to assessment like one on hand completed after 24-7-1980. ..." [Emphasis supplied] above observations clearly imply that change in rates of depreciation was amendment in procedural law and so it would apply to assessments pending as on date of amendment. We have seen above, that Appendix I to Part I is not procedural in its content but is part of section 32(1) and, therefore, forms part of substantive law. Substantive law cannot be interpreted in manner that it would apply to assessment for given year pending on 24-7-1980, though it did not apply to assessment for same year, which had been completed prior to 24-7-1980. 12. For reasons given above, we hold that rate of depreciation brought into effect from 24-7-1980 would not govern trucks and buses used prior to 24-7-1980. 13. departmental appeal is, therefore, eligible to succeed and, accordingly, be allowed. *** INCOME TAX OFFICER v. BHARAT ROADWAYS