Hi Priyanka,
There will be no legal hassle (under labor laws) if you declare increments in April and payout in October with the knowledge of employees. Labor laws do not stipulate or regulate increments; that is solely an employer's prerogative.
It would be advisable to communicate clearly and succinctly with employees about the change in the appraisal period from 6 months to one year and the reasons for it. Initially, it may be a matter of concern to them. Adding a personal touch by organizing a town-hall meeting to address this issue will be helpful. Alternatively, having respective department heads convey a common message to their staff about the change in the appraisal period as advised by HR would also be beneficial.
For the moment, employees will be happy to know that their six-month appraisal tenure will be counted and paid retroactively from April 1, 2009. However, they may question why this will be paid in Oct. '09, and this should be addressed.
Normally, to make such policy changes, HR must provide advance notice uniformly to employees to their reasonable satisfaction, not abruptly or piecemeal.
Be careful with the wording of the increment letters (anything given in writing and duly signed by management holds legal sanctity). If there is a deferment of the increment payable in April 2009, it must be accompanied by good reasons if provided in writing to dispel any message of malafide intentions from management.
It may be prudent to post a notice of "policy supersession/change on Performance Appraisal" on the main bulletin board for employees to read, followed by contact information. Subsequently, provide the increment letter in Sept. '09/Oct. '09. This approach should address concerns and dispel fears of job cuts or attrition, especially given the economic downturn and its repercussions.
Regards,
Priyanka Upasani
9850750998