DATES

Parameters

opcode  (Num)  [in]

specifies operation to perform:

Symbol	Value	Operation	Syntax
DTOP_CVTFMT	1	Convert one format (date1) to another (date2)	xcall DATES, 1, result, date1, date2
DTOP_DATEAFTER	2	Compute date (date2) which is a specified number of days (days) after date1	xcall DATES, 2, result, date1, date2, days
DTOP_DAYSAFTER	3	Compute number of days date1 is after date2	xcall DATES, 3, result, date1, date2, days
DTOP_YWD	4	Compute date2 based on year, week, day of week in X,6 or X,5 format of date1	xcall DATES, 4, result, date1, date2
DTOP_YWMD	5	Compute date2 based on year, month, week and day of week in X,6 format of date1	xcall DATES, 5, result, date1, date2
DTOP_EOM	6	Compute date2 as last day of month in date1	xcall DATES, 6, result, date1, date2
DTOP_ODTIM	7	Output formatted date (similar to ODTIM)	xcall DATES, 7, result, testdate, time, flags, outbuf'or'chan
DTOP_IDTIM	8	Input formatted date (similar to IDTIM)	xcall DATES, 8, result, inputstr, flags, outdate, outtime
DTOP_RANGE	9	Return out'of'range (F) <>0 if testdate is not between lodate and hidate (inclusive)	xcall DATES, 9, result, testdate, lodate, hidate, out'of'range
Definition file: ashell.def

 

result  (Num)  [out]

returns a code indicating if the operation was successful or what kind of error occurred:

Value	Meaning
0	OK
1	Function number out of range (1-9)
2	Error in conversion of input date
3	Invalid format for date
4	Improper number/type of parameters
5	Invalid format for days
6	Error locating file channel (opcode 7)

 

days  (Signed Num)  [out]

for DTOP_DAYSAFTER, returns number of days date2 is after date1

out'of'range  (Num)  [out]

for DTOP_RANGE, returns zero if testdate is within range defined by lodate and hidate (inclusive); else non-zero.

date1, date2, testdate, lodate, hidate

used for input and output, depending on the operation, with the format based on the way they are mapped:

MAP1 ADATE,S,8          ! MM/DD/YY format

MAP1 BDATE,S,10         ! MM/DD/CCYY format

MAP1 XDATE              ! Separated format (3 to 7 bytes)

   MAP2 MONTH,B,1

   MAP2 DAY,B,1

   MAP2 YEAR,B,1

   MAP2 DOW,B,1         ! 1=Monday...7=Sunday (optional)

   MAP2 YWEEK,B,1       ! Week of year (1-52)     (optional)

   MAP2 MWEEK,B,1       ! Week of month (1-5)     (optional)

   MAP2 MDAYS,B,1       ! Days in month (1-31)    (optional)

MAP1 IDATE,B,4          ! Internal true Julian

MAP1 BDATE,B,3          ! Std AMOS date (same as 3 byte XDATE

MAP1 CDATE,B,2          ! Century Julian (days since 1/1/1900)

MAP1 JDATE,B,2          ! Yearly Julian (days since start of yr)

MAP1 FDATE,F,6          ! Special case (0=today on input)

 

inputstr

should be set to the date and/or time be converted, with the time following the date (with a space separator) if both date and time are included. (Also see flags parameter, which indicates if date and/or time are present.) The date, if present, should be in MM-DD-{CC}YY or DD-MM-{CC}YY format, depending on your language definition file specification for date order. The separator character, however, need not be a dash or even match the language definition file; it can be any non-numeric character. The time format is HH:MM{:SS} {AM/PM}. Legal examples would be:

12/30/07 13:01

01-01-2007 10:15:33 PM

23:01:10

05.03.1915

 

If only two digits are specified for the year, it is assumed to be in the twentieth century (19xx) unless the SBR=CCYY is included in miame.ini, in which case it will determine the YY cutoff below which we assume 20xx instead of 19xx.

outdate  (F,6)

will return the internal format date, or zero if the date is not included in the input string. Note, however, that to access the individual separated fields within it, you need to assign the F,6 value to a B,4 which is mapped on top of the separated date structure, as in the following example:

MAP1 Sepdate

   MAP2 Mon,B,1              ! Month 1-12

   MAP2 Day,B,1              ! Day 1-31

   MAP2 Yr,B,1               ! Year-1900

   MAP2 Dow,B,1              ! Day of week (0=Mon, 6=Sun)

MAP1   Bdate,B,4,@Sepdate    ! B,4 version of Sepdate, as used by

                             !  the DATE system function

MAP1   Idate,F,6             ! F,6 version as needed by IDTIM

 

xcall IDTIM, StringFmt, Idate, Itime, Flags, Status

Bdate = Idate

Print "Separated date: ";Mon;Day;Yr;Dow

Bdate = DATE                 ! Get today's date (for comparison)

Print "Today's separated date: ";Mon;Day;Yr;Dow

 

outtime  (F,6)

will return the internal format time (i.e. seconds since midnight) or zero if the time is not present.

flags  (Num)

should be set to 0 to process both the date and time; 1 if the string is expected to contain only the time, and 2 if it is expected to contain only the date.

 

Counting Weeks

DATES.SBR counts the days of each week from Monday=1 to Sunday=7. (That may be a little strange, since most calendars show Sunday as the first day of the week instead of the last. But DATES.SBR is a port of some existing AMOS routine, so it was A-Shell's task to preserve the existing behavior, not to justify it.)

The weeks are counted like rows in a calendar, again taking into account that our calendar weeks start with Monday and end with Sunday. So for 2011, the first week had only 2 days: Saturday and Sunday. Jan 3 was the start of the 2nd week.

If you want to convert to a more standard calendar arrangement, where each week starts with Sunday and ends with Saturday, then just add +1 to Mon-Sat and for Sunday, set it back to 1 and add +1 to the week.

On the other hand, if you want to say that each week of the year, including the first one, has seven days, then the week is simply the "yearly Julian" (DATES option 6) divided by seven, truncating the fractional remainder and then addding one (so the first week is one rather than zero). Under that scheme, Mar 15 is the 74th day; 74/7 = 10.57; truncate to 10 and then add 1 to get the 11th week (which it is).