Many of us feel highly delighted when we receive letters/covers (not first day covers) franked with beautiful non-definitive stamps (commemorative or special stamps). However, there are too many instances that these nice letters/covers are franked with "old" stamps - for example letters/covers sent/postmarked in August 2010 franked with commemorative/special stamps issued in 1990s or even older. Honestly, the covers/letters with this type of situation look "odd" in my eyes. I don't know if you also have similar feeling when you receive these type of letters/covers. In philatelic words, this situation is known as out of period of use.
Now, you may ask what is the exactly the definition for within period of use. Well, it is very subjective, and it very much depends on individuals. I supposed the commemorative/special stamps used with two weeks after their date of release will definately be superb. Use within two months after the release date is also good; use within six months after the release date is not too bad; use within one year after the release date is acceptable........ well, the covers/letters would definately become more and more unpalatable when the date drags on.....
Are you on the same boat as I on the issue of period of use? hehehehehehehe...........
