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.

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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:

Values specified with PersistenceTime are converted to absolute expiration dates:

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