Adabas SQL Gateway & Dates

Hi, i need to know how to manage the dates using sql gateway

I need to the get the date of the system and substract 3 days back, for example is today is 26/09/2015, then i need a formula to get the date 3 days after, return 23/09/2015

in MSQL i use select dateadd(day,-3,getdate())

how can i do the same in adabas sql gateway??

Thank,

select timestampadd(SQL_TSI_DAY, -3, current_date())