racket/date: change current-date', add date*->seconds'

collects/plot/common/date-time.rkt

@@ -21,12 +21,6 @@
 
 ;; A date is always represented by the number of seconds since the platform-specific, UTC epoch
 
-(define (date*->seconds dt [local-time? #t])
-  (match-define (date* s mn h d m y wd yd dst? tz ns tz-name)
-    dt)
-  (+ (date->seconds (date s mn h d m y wd yd dst? tz) local-time?)
-     (/ ns 1000000000)))
-
 (define (date*->utc-seconds dt)
   (- (date*->seconds dt #f) (date-time-zone-offset dt)))
 

collects/racket/date.rkt

@@ -6,8 +6,9 @@
          racket/contract/base)
 
 (provide/contract
- [current-date (-> date?)]
+ [current-date (-> date*?)]
  [date->seconds ((date?) (any/c) . ->* . exact-integer?)]
+ [date*->seconds ((date?) (any/c) . ->* . real?)]
  [date->string ((date?) (any/c) . ->* . string?)]
  [date-display-format (parameter/c (symbols 'american 'chinese 'german 'indian 'irish 'julian 'iso-8601 'rfc2822))]
  [find-seconds (((integer-in 0 61)
@@ -23,7 +24,7 @@
  [julian/scalinger->string (exact-integer? . -> . string?)])
 
 (define (current-date)
-  (seconds->date (current-seconds)))
+  (seconds->date (* #i1/1000 (current-inexact-milliseconds))))
 
 ;; Support for Julian calendar added by Shriram;
 ;; current version only works until 2099 CE Gregorian
@@ -263,6 +264,12 @@
    (date-year date)
    local-time?))
 
+(define (date*->seconds date [local-time? #t])
+  (define s (date->seconds date local-time?))
+  (if (date*? date)
+      (+ s (/ (date*-nanosecond date) 1000000))
+      s))
+
 (define (find-seconds sec min hour day month year [local-time? #t])
   (define (signal-error msg)
     (error 'find-secs (string-append 

collects/scribblings/reference/time.scrbl

@@ -154,7 +154,7 @@ result is the result of  the last @racket[body].}
 
 @defproc[(current-date) date*?]{
 
-An abbreviation for @racket[(seconds->date (current-seconds))].}
+An abbreviation for @racket[(seconds->date (* 0.001 (current-inexact-milliseconds)))].}
 
 @defproc[(date->string [date date?] [time? any/c #f]) string?]{
 
@@ -175,12 +175,19 @@ Parameter that determines the date string format. The initial format
 is @racket['american].}
 
 @defproc[(date->seconds [date date?] [local-time? any/c #t]) exact-integer?]{
-Finds the representation of a date in platform-specific seconds. 
-The @racket[time-zone-offset] field of @racket[date] is ignored;
-the date is assumed to be in local time by default or in UTC
-if @racket[local-time?] is @racket[#f]. If
-the platform cannot represent the specified date, an error is
-signaled, otherwise an integer is returned. }
+Finds the representation of a date in platform-specific seconds.
+If the platform cannot represent the specified date,
+@exnraise[exn:fail].
+
+The @racket[week-day], @racket[year-day] fields of @racket[date] are
+ignored.  The @racket[dst?] and @racket[time-zone-offset] fields of
+@racket[date] are also ignored; the date is assumed to be in local
+time by default or in UTC if @racket[local-time?] is @racket[#f].}
+
+@defproc[(date*->seconds [date date?] [local-time? any/c #t]) real?]{
+Like @racket[date->seconds], but returns an exact number that can
+include a fraction of a second based on @racket[(date*-nanosecond
+date)] if @racket[date] is a @racket[date*] instance.}
 
 @defproc[(find-seconds [second (integer-in 0 61)]
                        [minute (integer-in 0 59)]

collects/tests/racket/date.rktl

@@ -3,7 +3,7 @@
 
 (Section 'date)
 
-(require mzlib/date)
+(require racket/date)
 
 (test #t date? (date* 0 0 0 1 1 -3000 0 0 #f -1000 0 "AST"))
 (test #t date? (date* 60 59 23 31 12 3000 6 365 #t 1000 999999999 "ZST"))
@@ -38,12 +38,21 @@
 (let* ([secs (find-seconds 1 2 3 4 5 2006)]
        [d-some-tz (seconds->date secs)]
        [d (struct-copy date d-some-tz
-                       [time-zone-offset -21600])])
+                       [time-zone-offset -21600])]
+       [d* (date* (date-second d) (date-minute d) (date-hour d)
+                  (date-day d) (date-month d) (date-year d)
+                  (date-week-day d) (date-year-day d) (date-dst? d)
+                  (date-time-zone-offset d)
+                  62500
+                  "MDT")]) 
   (define (test-string fmt time? result)
     (test (parameterize ([date-display-format fmt])
             (date->string d time?))
           fmt result))
   (test secs date->seconds d)
+  (test secs date*->seconds d)
+  (test (+ secs #e0.0625) date*->seconds d*)
+  (test (date->seconds d*) date->seconds (seconds->date (date*->seconds d*)))
   
   (test-string 'american #f "Thursday, May 4th, 2006")
   (test-string 'american #t "Thursday, May 4th, 2006 3:02:01am")

doc/release-notes/racket/HISTORY.txt

@@ -2,6 +2,8 @@ Version 5.3.2.2
 Added extflonums
 racket/extflonum: added
 racket/unsafe/ops: added extflonum operations
+racket/date: changed current-date to provide nanoseconds,
+ added date*->seconds
 
 Version 5.3.2.2
 Added file-truncate