postgresql - Ignoring seconds from timestamp postgres -

i running cron job every 1 minute notifying users events

select * events event_start = now()  - interval '30 minutes'

so can send users notification prior 30 mins of event

problem event start timestamp field if there difference in seconds wll not work ,so how can ignore seconds part .

you can use date_trunc() remove seconds:

select *  events  event_start = date_trunc('second', now())  - interval '30' minutes

GHI