---
url: >-
  /statelake/scripting-reference/functions-and-procedures/datetime-functions/dayspan.md
---

# DaySpan

**DaySpan** returns the number of days between two specified **TDateTime** values.

DaySpan differs from the function **DaysBetween**, in that **DaySpan** returns fractional or part days.

For example, **DaySpan** reports the difference between 1st February 11:59 PM and 2nd February 11:58 PM as 0.999305555560568 days span, because the day stops a second short of an entire day.

The ordering of the two dates doesn't matter - the number of days will not be negative.

**Declaration**: Function DaySpan(const ANow: TDateTime; const AThen: TDateTime): Double;

Examples follow.

```pascal
procedure OnMapEvent(var Value:Variant);
var
  vYear, vDate, vTween, vTween2 : TDateTime;
  vStrYear, vStrDate : string;
  vBetwix : double;
begin
 //Result is 4.0 days
  vBetwix := DaySpan(Date, Date+4);
  LogInfo(FloatToStr(vBetwix));

 //Result is 2.0 days
  vStrDate := '01-10-2023';
  vStrYear := '03-10-2023';
  vDate := StringToDateTime('dd/mm/yyyy',vStrDate);
  vYear := StringToDateTime('dd/mm/yyyy',vStrYear);
  vBetwix := DaySpan(vDate, vYear);
  LogInfo(FloatToStr(vBetwix));

 //Result is 0.999305555560568 days - 1 second short of a day
  vTween := EncodeDateTime(2023, 10, 01, 23, 59, 59, 999);
  vTween2 := EncodeDateTime(2023, 10, 02, 23, 58, 59, 999);
  LogInfo(FormatDateTime('yyyy-mm-dd hh:nn:ss.zzz', vTween));
  LogInfo(FormatDateTime('yyyy-mm-dd hh:nn:ss.zzz', vTween2));
  vBetwix := DaySpan(vTween, vTween2);
  LogInfo(FloatToStr(vBetwix));

 //Result is 1.0 day - seconds match
  vTween := EncodeDateTime(2023, 10, 01, 23, 59, 59, 999);
  vTween2 := EncodeDateTime(2023, 10, 02, 23, 59, 59, 999);
  LogInfo(FormatDateTime('yyyy-mm-dd hh:nn:ss.zzz', vTween));
  LogInfo(FormatDateTime('yyyy-mm-dd hh:nn:ss.zzz', vTween2));
  vBetwix := DaySpan(vTween, vTween2);
  LogInfo(FloatToStr(vBetwix));

end;
```