ExpirationDate
is an option for various functions that specifies when a persistent value should be treated as expired.
Details
- ExpirationDate can be used for PersistentSymbol and InitializationValue.
- Values can be given as absolute times or date and time specifications.
- Numerical values are treated as values given by UnixTime.
- The value Infinity (∞) or None can be used to specify that a persistent value should never expire.
- An expired persistent value is treated as nonexistent, and the underlying persistent object may be removed.
Examples
open allclose allBasic Examples (4)
Define a persistent value that expires at the beginning of the year 2024:
Verify the expiration date of the underlying persistent object:
Define a persistent value that expires at the beginning of next year:
Verify the expiration date of the underlying persistent object:
Define a persistent value that expires immediately:
Accessing an expired persistent value behaves as if it did not exist:
The default setting for ExpirationDate is to never expire:
Properties & Relations (1)
Values specified with PersistenceTime are converted to absolute expiration dates:
Text
Wolfram Research (2017), ExpirationDate, Wolfram Language function, https://reference.wolfram.com/language/ref/ExpirationDate.html.
CMS
Wolfram Language. 2017. "ExpirationDate." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/ExpirationDate.html.
APA
Wolfram Language. (2017). ExpirationDate. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/ExpirationDate.html