I am still relatively new to the Nihonto collecting world so please forgive me if this is a stupid question.   I have two swords that have a cutting edge of exactly 23.6 inches in length. I have heard that there was a time in Japanese history where the katana had a standard length of 23.6 inches and was later increased to 27 or 28 inches. Is this right? Others have told me that they are wakizashi's but i did not think wakizashi's were that long. Any help would be appreciated