Is my 24 hour eviction notice legal?

There is no such thing as a 24 hour notice under California law.

This is not sufficient in Washington. You can only be evicted by court order which comes from a lawsuit against you. The suit must be based upon one of several notices. You must be served with a 3-day notice for nuisance or waste or drug activity, a 3-day to pay or vacate, a 10-day notice to comply, or a 20-day notice to terminate. Once any one of these are served, before you can be evicted, the time must have expired. Then you must be served with a summons and complaint for the lawsuit. If you get served with a summons and complaint, you should contact an attorney right away.

No, unless your tenancy was related to your employment, the landlord must first give you a three day notice if you are in default of your lease, or otherwise a 30 to 60 day notice to terminate the rental agreement, depending upon whether you been there a year. Following the expiration of the notice, the landlord must file an eviction action.

Is it a court order? Then yes it is legal. If not a court order, probably not.