rom/utility/checkdate.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: CheckDate() - is a date valid ?
   6     Lang: english
   7 */
   8 #include "intern.h"
   9
  10 /*****************************************************************************
  11
  12     NAME */
  13 #include <utility/date.h>
  14 #include <proto/utility.h>
  15
  16         AROS_LH1(ULONG, CheckDate,
  17
  18 /*  SYNOPSIS */
  19         AROS_LHA(struct ClockData *, date, A0),
  20
  21 /*  LOCATION */
  22         struct Library *, UtilityBase, 22, Utility)
  23
  24 /*  FUNCTION
  25         Examine the date described in the ClockData structure and
  26         determine whether it is a valid date. In particular this
  27         checks whether the ranges of the fields are within normal
  28         limits.
  29
  30         This function does not check whether the wday field of the
  31         ClockData structure is valid.
  32
  33     INPUTS
  34         date        -   A ClockData structure desribing the date
  35                         to check.
  36
  37     RESULT
  38         If the date is valid, the number of seconds from midnight
  39         1-Jan-1978 AD to the date, or 0 if the date is invalud.
  40
  41     NOTES
  42         The date 01-Jan-78 00:00:00 is actually returned as invalid.
  43
  44         This also assumes that the ClockDate refers to a date in the
  45         Gregorian calendar. (60 sec/min, 60 min/hour, 24 hr/day,
  46         12 months/year).
  47
  48     EXAMPLE
  49
  50     BUGS
  51         Does not check whether the 29/2 is valid outside of a leap year.
  52
  53     SEE ALSO
  54         Amiga2Date(), Date2Amiga()
  55
  56     INTERNALS
  57         Since all the values are unsigned, we don't have to check for < 0
  58         in fields which range from 0 ... n.
  59
  60     HISTORY
  61         29-10-95    digulla automatically created from
  62                             utility_lib.fd and clib/utility_protos.h
  63
  64 *****************************************************************************/
  65 {
  66     AROS_LIBFUNC_INIT
  67
  68     /* Note: 60!!! This is in case of any future leap seconds... */
  69     if( date->sec > 60 )
  70         return 0;
  71
  72     if( date->min > 59)
  73         return 0;
  74
  75     if( date->hour > 23)
  76         return 0;
  77
  78     /* XXX: When does the year become invalid? */
  79     if( date->year < 1978 )
  80         return 0;
  81
  82     if( date->wday > 6)
  83         return 0;
  84
  85     if( date->mday < 1 )
  86         return 0;
  87
  88     switch( date->month )
  89     {
  90         /* 30 days hath September, April, June and November */
  91         case 4:
  92         case 6:
  93         case 9:
  94         case 11:
  95             if(date->mday > 30)
  96                 return 0;
  97             break;
  98
  99         /* And all the rest have 31 ... */
 100         case 1:
 101         case 3:
 102         case 5:
 103         case 7:
 104         case 8:
 105         case 10:
 106         case 12:
 107             if(date->mday > 31)
 108                 return 0;
 109             break;
 110
 111         /*  Except February with has 28, or 29 on a leap year,
 112             should I check whether this is a leap year or not?
 113         */
 114         case 2:
 115             if(date->mday > 29)
 116                 return 0;
 117             break;
 118
 119         /* This also traps invalid month numbers */
 120         default:
 121             return 0;
 122     } /* switch(date->month) */
 123
 124     return Date2Amiga(date);
 125
 126     AROS_LIBFUNC_EXIT
 127 } /* CheckDate */