x$expires will be returned if it is not NULL. Otherwise, the
(character representation of the) exiration date of the first-to-expire of
the members will be returned.
# S3 method for spread
expires(x, Date, expired = TRUE, silent = FALSE, ...)A `Date` value representing the spread expiration. The value is taken from the spread itself when available; otherwise, it is determined from the first-expiring member. May return `NULL` if no expiration can be determined.
Can be a Date or character string. When expires is a
vector, the retuned value will be one of the two values of expires
that are closest to Date. (which one will be determined by the value
of expired).
TRUE/FALSE. This determines which date will be used when
expires is a vector. If expired is TRUE the date
returned will be the last one before Date. If expired is
FALSE the first one after Date will be returned.
Garrett See
expires.instrument