Informix datetime: How to subtract 15 Minutes

Question

How can I do this MySQL statement in an IBM Informix?

select type, channel, teilnr, starttime, endtime, usedtime, host 
from online_time 
where starttime < DATE_SUB(NOW(),INTERVAL 15 MINUTE)
order by starttime desc 

I tried this one in Informix, but it gave a syntax error.

select type, channel, teilnr, starttime, endtime, usedtime, host 
from online_time 
where starttime < subdate(CURRENT, INTERVAL "15" MINUTES)
order by starttime desc 

Answer 1

select type, channel, teilnr, starttime, endtime, usedtime, host 
from online_time 
where starttime > (CURRENT - 15 UNITS MINUTE) 
order by starttime desc