A reasonable amount of sick leave is as much as you medically need.
However what is a reasonable amount of sick leave is relative to the hours you work, how hard you work, and the size of the business.
If your boss never takes a day off unless they are really ill, then I wouldnt expect you to shirk a bit of light work either. If you had a cold, then I wouldnt want you in, untill the virus side of it had gone away. If it was self indulgenced, eg drinking too much the night before,,, Then hard luck, get yourself into work, and stop wasting the countries money!
As a policy manager, I would lookinto other policies, get legal advice on it, and look at how long the other employers have been in position.
Council sick policies are freely available to the public, this might be a good starting point.
Good luck.. writing the policy is normally the easy bit, enforcing it
