How to write an SQL to pull data for Day 1 of the current month

[AB1130]

I'm trying to write a workflow that will pull data for the first day of whatever the current month is. Any ideas on how to write the SQL? 

[cjaneczko]

This will give you the first of the current month. You can use this as a filter for whatever date field you are bringing into the WF. 

datetimetrim(DateTimeNow(),'firstofmonth')

[AB1130]

The SQL editor isn't recognizing datetimetrim. I'm connected to the Oracle database.