cache basics

2 main options. 

• $ZDATE Function offers a broad range of date presentations and conversions
• System.SQL*  contains most popular SQL based Date functions as
  • DATE
  • DATEADD
  • DATEDIFF
  • DATENAME
  • DATEPART
  • DAYNAME
  • DAYOFMONTH

  • DAYOFWEEK

  • DAYOFYEAR
  • LASTDAY
  • MONTH
  • MONTHNAME
  • QUARTER
  • TOCHAR
  • TODATE
  • TOTIMESTAMP
  • WEEK
  • YEAR

Hi

If the Ens package is available to you, then I find very useful the ConvertDateTime() method of the Ens.Util.Time class.

For example, if I want to convert this date: “20181220” to “20-12-2018”, then I use the ConvertDateTime() method like this:

SET ConvertedDt =##class(Ens.Util.Time).ConvertDateTime("20181220","%Y%m%d","%d-%m-%Y")

The patterns that I use more frequently are:

%Y    year including the century, as a 4-digit number (0000-9999)
%y    year within a century as a number (00-99)
%m    month as a 2-digit number (01-12)
%#m    month as a number (1-12) without leading zeros    
%d    day of the month as a 2-digit number (01-31)
%#d    day of the month as a number (1-31) without leading zero
%H    hour in 24-hour format as a 2-digit number (00-23)
%M    minute as a 2-digit number (00-59)
%S    second as a 2-digit number (00-60) (60 for leap seconds)
%N    fractional second in milliseconds as number (000-999)

You can read more details about the Ens.Util.Time class including the full list of the supported patterns here:

https://docs.intersystems.com/latest/csp/documatic/%25CSP.Documatic.cls?PAGE=CLASS&LIBRARY=ENSLIB&CLASSNAME=Ens.Util.Time

I hope it helps.

Regards

Stelios