+; now the same for dates
+(eval-when (:compile-toplevel :load-toplevel)
+(defun replace-string (string1 search-string replace-string &key (test #'string=))
+ "Search within string1 for search-string, replace with replace-string, non-destructively."
+ (let ((replace-string-length (length replace-string))
+ (search-string-length (length search-string)))
+ (labels ((sub-replace-string (current-string position)
+ (let ((found-position (search search-string current-string :test test :start2 position)))
+ (if (null found-position)
+ current-string
+ (sub-replace-string (concatenate 'string
+ (subseq current-string 0 found-position)
+ replace-string
+ (subseq current-string (+ found-position search-string-length)))
+ (+ position replace-string-length))))))
+ (sub-replace-string string1 0))))
+);eval-when
+
+(defmacro wrap-time-for-date (time-func &key (result-func))
+ (let ((date-func (intern (replace-string (symbol-name time-func)
+ (symbol-name-default-case "TIME")
+ (symbol-name-default-case "DATE")))))
+ `(defun ,date-func (number &rest more-numbers)
+ (let ((result (apply #',time-func (mapcar #'date->time (cons number more-numbers)))))
+ ,(if result-func
+ `(funcall #',result-func result)
+ 'result)))))
+
+(wrap-time-for-date time=)
+(wrap-time-for-date time/=)
+(wrap-time-for-date time<)
+(wrap-time-for-date time>)
+(wrap-time-for-date time<=)
+(wrap-time-for-date time>=)
+(wrap-time-for-date time-max :result-func time->date)
+(wrap-time-for-date time-min :result-func time->date)
+
+(defun date-compare (date-a date-b)
+ (time-compare (date->time date-a) (date->time date-b)))