51cd1206_JSON_Web_Token__JWT___Claim_Syntax
[Claim Name] exp [JSON Value Type] number [Claim Semantics] The exp (expiration time) claim identifies the expiration time on or after which the token MUST NOT be accepted for processing. The processing of the exp claim requires that the current date/time MUST be before the expiration date/time listed in the exp claim. Implementers MAY provide for some small leeway, usually no more than a few minutes, to account for clock skew. This claim is OPTIONAL. [Claim Syntax] 
IntDate
I n t D a t e
S t r i n g O r U R I
S t r i n g
JSON Web Token (JWT)
Claim Syntax