Can sick time be applied towards retirement age requirement?

Unfortunately, the answer is no. It can add to your length of service to increase the multiplier to 1.1% but you had to already be age 62 at the time of retirement.

How many days/ months does a 1000 hrs of sick leave equals to add to service time when retiring? What does a full month means: calendar month or a month based on your service computation date?

Madeline, 1000 hours of sick leave equals 5 months and 23 days in the retirement world because to convert your sick leave to creditable service, OPM uses a 2087 hour sick leave chart, which can be found on page 51 at the following link: https://www.opm.gov/retirement-services/publications-forms/csrsfers-handbook/c050.pdf
Forgive me when I try to explain how this works because it is complicated and lengthy. Take the number of hours you have, as in your example 1000, then find that number on the chart. IF your number of sick leave hours isn’t displayed on the chart, you round up to the next higher number, again, in this example we rounded up to 1003 hours. When you read the rules for calculating a retirement, you will find that retirements are calculated on full years and full months of service and odd days are dropped. One would think, in this example, that you would be losing 23 days or 133 hours of sick leave. However, you also must be aware that the first step in calculating length of service is to subtract your retirement service computation date from your retirement date. That gives you total creditable service. Then add your total sick leave credit to the previous total. At that point you drop any odd days that do not add up to 30. Another piece of HR trivia, for retirement purposes, 30 days = a month, 174 hours of sick leave = a month, 5.8 hours of sick leave = a day, and 2087 hours of sick leave = a year.