Notice Before Unilateral Termination of Employment Contract
The concept of notice before the unilateral termination of the employment contract, either by the employer or the employee, is based on the principle of enabling the other party to prepare for making suitable alternative arrangements. However, this condition is normally relaxable for the employee by providing a buy-out option, subject to the employer's acceptance. Similarly, the employer may pay the notice salary in lieu of notice if provided for in the contract. Otherwise, non-compliance by either party would constitute a breach of the contract, resulting in damages if contested by the aggrieved party.
If the employer finds an immediate substitute to fill the vacancy caused by an employee serving the notice period, they can make a counteroffer to pay the salary for the unserved notice period to the resigning employee and relieve them immediately. Similarly, under the same pretext of organizational interest, the employer has the discretion to turn down the employee's buy-out option. The normal practice followed by most organizations is not allowing long leave during the notice period. This is the reason behind the proportionate extension of the notice period, which cannot be legally faulted.
Handling Notice Period During Unforeseen Circumstances
Probably, the poster might have an alternative job at the expiry of the 90-day notice period during which they met with an unfortunate accident. In such a situation, they can ask the prospective employer to extend the joining time or request the current employer to either waive the notice period of 60 days they were on leave due to the accident or permit them to buy it out.