Lease with no specific dates on it
We signed a lease that has no set time frame such as month to month, six months, or one year. So how long are we obligated to the lease? Can we move out anytime or do we have to give 30, 60, 90 days notice? There is a section in the lease that states the owners realize we are military and subject to mandatory military moves in the event we PCS we are to give them 90 days notice.

Want Deposit Back
I rented an apartment (800/mo.) and paid a $400 sec. deposit.
The apartment was on a month to month lease. The day I was to move in, I told the landlord I needed to back out of the lease and get my deposit back. This is due to last minute job relocation. The landlord refused to refund my deposit because she had to hold the apartment for me. I told her I was willing to give her half of the deposit for the trouble. She still refused to return my deposit. Do I have a case?
Thank you.

My mother owns a property in the city I live. She lives in another city. I leased the property for her and signed it as the landlord in my name. It was a 12 month lease. The lease is a standard NC Residential Lease Agreement. Tenants have paid the 12 months and are now in a month to month lease. My mother wants to ask them to leave with a 30 day notice. It is mid April and she wants the 30 days to be effective now having them vacate mid May. The tenant had paid all of April. Question: does the 30 day notice have to be effective starting at the END of April, which was paid in full or can the notice be effective now so they have until mid May to vacate.