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DosDateTimeToVariantTime function (oleauto.h)

  • Article

Converts the MS-DOS representation of time to the date and time representation stored in a variant.

Syntax

INT DosDateTimeToVariantTime(
  [in]  USHORT wDosDate,
  [in]  USHORT wDosTime,
  [out] DOUBLE *pvtime
);

Parameters

[in] wDosDate

The MS-DOS date to convert. The valid range of MS-DOS dates is January 1, 1980, to December 31, 2099, inclusive.

[in] wDosTime

The MS-DOS time to convert.

[out] pvtime

The converted time.

Return value

The function returns TRUE on success and FALSE otherwise.

Remarks

MS-DOS records file dates and times as packed 16-bit values. An MS-DOS date has the following format.

Bits Contents
0–4 Day of the month (1–31).
5–8 Month (1 = January, 2 = February, and so on).
9–15 Year offset from 1980 (add 1980 to get the actual year).
 

An MS-DOS time has the following format.

Bits Contents
0–4 Second divided by 2.
5–10 Minute (0–59).
11–15 Hour (0– 23 on a 24-hour clock).
 

The DosDateTimeToVariantTime function will accept invalid dates and try to fix them when resolving to a VARIANT time. For example, an invalid date such as 2/29/2001 will resolve to 3/1/2001. Only days are fixed, so invalid month values result in an error being returned. Days are checked to be between 1 and 31. Negative days and days greater than 31 results in an error. A day less than 31 but greater than the maximum day in that month has the day promoted to the appropriate day of the next month. A day equal to zero resolves as the last day of the previous month. For example, an invalid date such as 2/0/2001 will resolve to 1/31/2001.

Requirements

Requirement Value
Target Platform Windows
Header oleauto.h
Library OleAut32.lib
DLL OleAut32.dll