Function
Returns a string representation of a date, conforming to the ISO 8601 standard.
as-iso8601-string date #key precision => iso8601-string
<date>.
<integer>. Default value: 0.
<string>.
system
date
Returns a string representation of date using the format identified by International Standard ISO 8601 (for example, "19960418T210634Z"). If precision is non-zero, the specified number of digits of a fraction of a second are included in the string (for example, "19960418T210634.0034Z").
The returned string always expresses the time in Greenwich Mean Time. The iso8601-string init-keyword for <date>, however, accepts ISO 8601 strings with other time zone specifications.