Delphi Basics : StrToDate command

DelphiBasics

StrToDate
Function

Converts a date string into a TDateTime value

SysUtils unit

1	function StrToDate(const Date string):TDateTime;
2	function StrToDate (const Date string; const FormatSettings TFormatSettings:TDateTime;

Description

The StrToDate function attempts to convert a date as a string Date into a TDateTime value.

The date string must adhere to the format of the ShortDateFormat value, and use the DateSeparator character to separate the day, month and year values.

The default format in the UK is day/month/year, where :

The day	must be 1..31 (depending on month/year)
The month	must be 1..12
The year	must be 0..9999 (optional)

Omitting the year results in the use of the current year.

Note that year 0015, for example, must be given with the century digits; 15 on its own would be seen as a recent year.

If the year is 2 digits, the century is determined by the TwoDigitYearCenturyWindow value.

The time is set to 0 - the start of the specified day.

Any errors in the date string will yield EConvertError.

Version 2 of this function is for use within threads. You furnish the FormatSettings record before invoking the call. It takes a local copy of global formatting variables that make the routine thread safe.

Related commands

DateSeparator		The character used to separate display date fields
DateToStr		Converts a TDateTime date value to a string
ShortDateFormat		Compact version of the date to string format
StrToDateTime		Converts a date+time string into a TDateTime value
StrToTime		Converts a time string into a TDateTime value
TwoDigitYearCenturyWindow		Sets the century threshold for 2 digit year string conversions

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Example code : Showing 2 and 4 digit year date string conversions

var
  myDate : TDateTime;

begin
  myDate := StrToDate('15/03/75');
  ShowMessage('15/03/75   = '+DateTimeToStr(myDate));
  myDate := StrToDate('01/01/2075');
  ShowMessage('01/01/2075 = '+DateTimeToStr(myDate));
end;

Show full unit code

15/03/75 = 15/03/1975
01/01/2075 = 01/01/2075