DTDateTimeStringToQwordDateTime

Converts a formatted date & time string to QWORD values. On return RAX contains the date information and RDX the time information.

DTDateTimeStringToQwordDateTime PROTO lpszDateTimeString:QWORD, DateFormat:QWORD

Parameters

lpszDateTimeString - Pointer to a buffer containing the date & time string to convert to QWORD values. The format of the date & time string is determined by the DateFormat parameter.
DateFormat - Value indicating the date & time format used in the buffer pointed to by lpszDateTimeString parameter. The parameter can contain one of the following constants as listed in the DateTime Formats page and as defined in the DateTime.inc include file.

Returns

On return RAX will contain the date information in the following format:

RAX Register Bits:

+--------------------------------------------------+------------------------+------------+-----------+
| DWORD                                            | WORD                   | BYTE       | BYTE      |
+--------------------------------------------------+------------------------+------------+-----------+
| Bits 63-32                                       | Bits 31-16             | Bits 15-8  | Bits 7-0  |
+--------------------------------------------------+------------------------+------------+-----------+
| Not used - Not applicable                        | Century Year           | Month      | Day       |
+--------------------------------------------------+------------------------+------------+-----------+
| N/A                                              | CCCCYY                 | MM         | DD        |
+--------------------------------------------------+------------------------+------------+-----------+

On return RDX will contain the time information in the following format:

RDX Register Bits:

+--------------------------------------------------+------------+------------+-----------+-----------+
| DWORD                                            | BYTE       | BYTE       | BYTE      | BYTE      |
+--------------------------------------------------+------------+------------+-----------+-----------+
| Bits 63-32                                       | Bits 31-23 | Bits 23-16 | Bits 15-8 | Bits 7-0  |
+--------------------------------------------------+------------+------------+-----------+-----------+
| Not used - Not applicable                        | Hour       | Minute     | Second    | Millisec  |
+--------------------------------------------------+------------+------------+-----------+-----------+
| N/A                                              | HH         | MM         | SS        | MS        |
+--------------------------------------------------+------------+------------+-----------+-----------+

Notes

The registers always return the information in the format shown in the tables above, and do not change regardless of the DateFormat parameter.

The DateFormat parameter is used to indicate the format of the date & time string being passed to DTDateTimeStringToQwordDateTime.

Some information may be unavailable to convert if the passed DateTime string does not contain enough information. For example if only year information is in the DateTime string, then the DWORD date and DWORD time will be based only on that.

To prevent this, always pass a full date time string of CCYYMMDDHHMMSSMS format or similar (DDMMCCYYHHMMSSMS or MMDDCCYYHHMMSSMS)

To retrieve the various values of the date & time QWORD values you can use the following as an example:

Example

.data
DateTimeStringValue db "2008/03/21 16:21:01:00",0

.data?
DateValue dq ?
TimeValue dq ?
CentYear dq ?
Year dq ?
Month dq ?
Day dq ?

.code
Invoke DTDateTimeStringToQwordDateTime, Addr DateTimeStringValue, CCYYMMDDHHMMSSMS
mov DateValue, rax ; Save date info in rax to a data variable
mov TimeValue, rdx ; Save time info in rdx to a data variable

; save day, month, year and century info to data variables
mov rdx, DateValue ; use rdx as our work place

xor rax, rax ; clear register
mov al, dl ; dl contains day info
mov Day, rax ; save day info DD in dl to a data variable

xor rax, rax ; clear register
mov al, dh ; dh contains month info
mov Month, rax ; save month info MM in dh to a data variable

shr edx, 16 ; century and year are now in dx part of the register
mov CentYear, rdx ; save century and year info CCYY to a data variable

xor rax, rax ; clear register
mov al, dl ; dl contains YY part of year
mov Year, rax ; save year info in dl to a data variable