JUDGMENT Tinlianthang Vaiphei, J. 1. This writ petition was originally filed by the husband of the deceased, who died on 1-12-2006 during the pendency of the writ petition, and was thereafter substituted by the present petitioner vide the order dated 30-11-2007 passed by this Court in Misc. Case No. 4121 of 2007. The interesting question of law raised in this writ petition is whether the period of absence of the deceased from 14-10-1973 to 3-5-1990, which was subsequently regularized by the respondent authorities by treating such period as "Dies Non", can be counted for the purpose of pension benefit? The controversy arose on the following facts and circumstances: The deceased joined the post of Forest Guard on 1-5-1956 at the Office of the Forest Range Officer, Lumding and was continuing in that post in that capacity till 1973 by drawing his salaries. However, he had to remain absent from between 14-1-1973 and 3-5-1990 due to mental illness. After his recovery from the illness, he approached the respondent authorities for work. The respondent No. 4 again appointed him as Gate Chowkidar on 24-1-1985. Subsequently, he was appointed as Forest Guard with effect from 2-5-1990; his service was eventually confirmed on 1-12-1995. The deceased retired from service on 31-3-1996 on attaining the age of superannuation. The respondent authorities thereafter counted the total period of his service i.e. from the date of his second appointment as 2-5-1990 to the date of his superannuation as 31-1-1996 to be five years, ten months and twenty-nine days. He, therefore, received a sum of Rs.2,227/- as his monthly pension, which was fixed on the basis of his service for the period between 2-5-1990 and 31-1-1996. It would appear that the period of absence from duty from 14-1-1973 to 3-5-1990 was subsequently regularized by the respondents by treating such period as "Dies non" to bridge the gap between previous service and existing service without giving the benefit of pay, increment, leave, pension to the deceased for that period. The deceased made representation to the respondents to count the said period of his absence without leave for the purpose of pension, but the same proved futile. This prompted him to file this writ petition for appropriate relief. 2. The writ petition is contested by the respondent authorities by filing their affidavit-in-opposition. The deceased made representation to the respondents to count the said period of his absence without leave for the purpose of pension, but the same proved futile. This prompted him to file this writ petition for appropriate relief. 2. The writ petition is contested by the respondent authorities by filing their affidavit-in-opposition. The case of the answering respondents is that the total period of qualifying service for entitlement of pension under the Assam Pension Rules, 1968 is 20 years. The deceased was admittedly appointed as Forest Guard on 1-5-1956, but he was found absent from duty without leave for the period indicated in the writ petition; due to his unauthorised absence, he was not in service in that period. It is, therefore, submitted that the deceased has failed to make out any case for invoking the extra-ordinary jurisdiction of this Court, and the writ petition is liable to be dismissed. 3. From the letter dated 26-2-2004 addressed to the Principal Chief Conservator of Forest, Assam by the Under Secretary to the Govt. of Assam, Environment & Forest Department, it has been admitted by the State-respondents that the absence from duty by the deceased for the period of 17 years, 3 months and 18 days was due to mental illness. It may be noted that this prompted the State-respondents to regulate such period of absence by treating it as "dies non". Such period was not meant to give any benefit of pay, increment, leave, pension, etc., but "to bridge the gap between previous service and existing service". Rules 64 and 65 of the Assam Services (Pension) Rules, 1969 ("the Rules" for short) deals with the effect of interruptions in service, which are in the following terms: 64. Interruptions.--An interruption in the service of an officer entails forfeiture of his past service except in the following cases: (a) Authorised leave of absence. (b) Unauthorised absence in continuation of authorised leave of absence so long as the office of the absentee is not substantively filled; if his office is substantively filled, the past service of the absentee is forfeited. (c) Suspension immediately followed by reinstatement, which need not be to the same office or where the officer died or is permitted to retire or is retired while under suspension. (d) Abolition of post or loss of appointment owing to reduction of establishment. (c) Suspension immediately followed by reinstatement, which need not be to the same office or where the officer died or is permitted to retire or is retired while under suspension. (d) Abolition of post or loss of appointment owing to reduction of establishment. Note.--The above clause (d) applies only in case of abolition of permanent office or loss of permanent appointment. (e) Transfer to non-qualifying service in an establishment under Government control. The transfer must be made by a competent authority; an officer who voluntarily resigns qualifying service cannot claim the benefit of this exception. Transfer to grant in aid school entails forfeiture. (f) Transfer to service on household establishment of the Governor. (g) Time occupied in transit from one appointment to another, provided that the officer is transferred under the orders of competent authority, or, if he is non-gazetted officer, with the consent of the head of his old office. 65. The authority who sanctions the pension may commute retrospectively periods of absence without leave into leave without allowances. 4. In the instant case, though the deceased was found to be in an unauthorized absence from duty for 17 years, three months and 18 days, the State-respondents did not expressly declare such period of his absence to be an interruption in service entailing forfeiture of his past service. They merely declared such period of absence as "dies non". The term "dies non" is nowhere defined in the Rules. The decision of the Government of India reproduced in Swamy's "Pension Compilation", 19th Edn., p. 65, will be instructive: Treatment of wilful absence from duty not regularized.--wilful absence from duty, even though not covered by grant of leave does not entail loss of lien. The period of absence not covered by grant of leave shall have to be treated as 'dies non' for all purposes, viz. increment, leave and pension. Such absence without leave where it stands singly and not in continuation of any authorized leave of absence will constitute an interruption of service for the purpose of pension and unless the pension sanctioning authority exercises its powers under Article 421, Civil Service Regulations [now Rule 27 of the CCS (Pension) Rules] to treat the period as leave without allowance, the entire past service will stand forfeited. 5. Reading the aforesaid decision carefully unmistakably conveys the idea that unauthorized absence from duty per se need not entail forfeiture of past service. 5. Reading the aforesaid decision carefully unmistakably conveys the idea that unauthorized absence from duty per se need not entail forfeiture of past service. To entail forfeiture of past service of an employee, it has to be shown that the unauthorized absence is wilful. In other words, unless the unauthorized absence is proved to be wilful, the leave sanctioning authority is empowered by Rule 65 to retrospectively commute such period of absence without leave into leave without allowance. What is 'wilful absence from duty' is recently explained by the Apex Court in Krushnakant B. Parmar v. Union of India and another, (2012) 3 SCC 178 in the following manner: 16. In the case of the appellant referring to unauthorised absence the disciplinary authority alleged that he failed to maintain devotion to duty and his behaviour was unbecoming of a government servant. The question whether "unauthorised absence from duty" amounts to failure of devotion to duty or behaviour unbecoming of a government servant cannot be decided without deciding the question whether absence is wilful or because of compelling circumstances. 17. If the absence is the result of compelling circumstances under which it was not possible to report or perform duty, such absence cannot be held to be wilful. Absence from duty without any application or prior permission may amount to unauthorised absence, but it does no always mean wilful. There may be different eventualities due to which an employee may abstain from duty, including compelling circumstances beyond his control like illness, accident, hospitalisation, etc. but in such case the employee cannot be held guilty of failure of devotion to duty or behaviour unbecoming of a government servant. (Bold letters mine) 6. As already noticed, the letter dated 26-2-2004 at Annexure-G, the respondent No. 2 has recognized the fact that the absence of the deceased was occasioned by the mental illness. Thus, on the undisputed facts on record that the unauthorised absence of the deceased was occasioned by mental illness, there is no difficulty in holding that his absence from duty, even though unauthorised, cannot be held to be wilful absence from duty. Thus, on the undisputed facts on record that the unauthorised absence of the deceased was occasioned by mental illness, there is no difficulty in holding that his absence from duty, even though unauthorised, cannot be held to be wilful absence from duty. Consequently, the respondent No. 2 has committed an error of law in treating the period of absence from duty of the deceased for the period in question as dies non merely "to bridge the gap between previous service and existing service without giving to the incumbent any benefit of pay, increment, leave, pension, etc. for that period. The respondent No. 2 in issuing the impugned order has apparently failed to notice the provisions of Rule 64 and Rule 65 of the Rules; this is non-application of mind. The deceased was under Rule 65 of the Rules entitled to have his period of absence without leave commuted retrospectively into leave without allowances. In the result, this writ petition succeeds. The impugned letter dated 26-2-2004 (Annexure-G) is hereby quashed. The respondent No. 2 shall now commute retrospectively the period of absence of the deceased without leave from 14-1-1973 to 3-5-1990 into leave without allowance in accordance with Rule 65 of the Rules, count the entire past services of the deceased w.e.f. 1-5-1956 including the said period of absence for the purpose of pension and family pension and thereafter pay all the pension and family pension admissible to the deceased under the rules to the petitioner. Such payment shall be made by the respondent authorities to the petitioner within a period of three months from the date of receipt of the certified copy of this judgment from her. No costs.