Whenever the date of expiration of any credential occurs while the person holding the credential is in the active military service of the United States of America or of the State of California, including active service in any uniformed auxiliary of, or to, any branch of such military service created or authorized as such auxiliary by the Congress of the United States of America or by the Legislature of the State of California or in the service of the United States Merchant Marine, or in the full-time paid service of the American Red Cross, during any national emergency declared by the President of the United States of America, or during a war in which the United States of America is engaged, or within six months after such person honorably leaves such service or has been placed on inactive duty, the credential is hereby continued in force until six months after such person honorably leaves such service or has been placed on inactive duty.
The holder of a credential so extended shall be entitled to a renewal of the credential prior to its date of expiration as herein fixed, subject to provisions of this code relating to the renewal of credentials.