Re: Fmla
Assuming that the FMLA applies as you said, then you are allowed to take "intermittent" or reduced schedule leave while protected. Thus, a 6-hour schedule is acceptable. And you are correct in that the company should see this as helpful. In fact, the FMLA asks employees to try to work out a schedule that is least disruptive if at all possible.
I recommend talking to HR or a trusted officer. If your FMLA certification (did the company ask you to get one from the doctor?) does not make clear that you are needed to care for your spouse (cooking, cleaning, psychological care, help with medicine, etc.), then you should provide it if the company asks for it.
If you can not get anywhere, you should immediately file a complaint with the local office of the US DOL (dol.gov). Let the employer know you have done so and that they may not retaliate in any way for your doing so. (Be diplomatic. Just tell them you believe you have FMLA rights and you have asked DOL to help you. Of course, companies often get defensive and take stupid, retaliatory action even though it is illegal, so be forewarned and careful.)
As it is, if the employer does not allow the 6-hour schedule even though you are covered by the FMLA and needed to care for your husband, they are violating both the leave provisions and the provisions that say they may not interfere with FMLA rights.
The regulations are found at 20 C.F.R Part 825 (dol.gov has them), but they are not easy to understand if you do not work with them all the time. The DOL of course can help, or you could hire your own attorney. But the DOL is free, so start there.
Last, check your employee handbook to see if that gives you any rights, too, regarding reduced schedules and leave.
Good luck.
Jeff Sheldon
Jeffrey L. Sheldon
The Sheldon Law Firm
CAVEAT: This is only general advice based on limited facts and knowledge of the situation. It thus can not be relied upon as legal advice nor is the author responsible or liable for any actions by the parties involved in the matter.