Postage stamps are good for any point in time. The US hasn't devalued postage since the Civil War. You can always ask the postal clerk at the time of sale how long you have to use it.
Can I sale my Thomas Jefferson 1802-1809 stamp ? And to who ?
We can use the recent date stamp paper for old or back date agreement. To keep on record and to be inforced by law, two or more persons enter into an agreement to safeguard the intrests of eachother.
You can remove date stamp from image using Inpaint http://www.theinpaint.com/inpaint-how-to-remove-date-stamp-from-photo.html
In this case you either use time/date stamp or automatic text.
I'm not able to provide real-time information on the availability of the Barbara Jordan stamp for sale. You may want to check with your local post office or visit the official USPS website for the most up-to-date information on available stamps for purchase.
The "sale by" date lets the consumer know how long this item will be fresh or at its best. The stock employees also use this date to discard and replace items that are past their freshness date.
The date by which the manufacturer or shop should have sold the goods. After this date they should not be on the shelves for sale. This sell by date is NOT a use by date. The use by date tells the customer not to use the product after this date because it is now no longer fit to use. This is particularly important for medicines and perishable foodstuff.
you should date stamp a letter because then others know when it came in and when in can be distributed
Simplest and fastest way is to purchase a rubber date stamp. You can stamp the date on the back of the card above the manufacturer logo.
validity is not 6 months from the date of purchase as mentioned in earlier answer. There is no validity period fixed under law for using the stamp paper from the date of purchase. For claiming refund of the stamp papers there is a time limit. Therefore, the stamp paper can be used even after expiry of six months.
post card with 1 cent stamp date of 1911
date stamp