Date Floor
Returns the floor of Date with respect to Date Part. In other words, the function determines which Date Part interval contains Date, and returns a string representing the starting date/time value of that interval.
Arguments
This function has the following arguments:
 Date
Date: Text string specifying the date whose floor is to be returned. This must be either a formatted date/time string or a Java standard date/time argument in milliseconds from Jan 1, 1970.
 Date Part
Date Part: Text string specifying the date part with respect to which the specified date’s floor is to be returned. Specify 
s, 
m, 
h, 
d, 
w, 
M, 
q or 
y for seconds, minutes, hours, days, weeks, months, quarters, or years.
 Date Format
Date Format: Text string specifying the format of the function result. Specify a pattern string suitable for use with the Java 
SimpleDateFormat class. For example, the format 
MMMM dd, yyyy hh:mm:ss a results in dates of the form exemplified by 
August 30, 2003 05:32:12 PM. If no 
Date Format is given, the string is returned in the form exemplified by 
08/30/03 05:32 PM. Use 
q, 
qqq or 
qqqq for short, medium or long versions of quarter notation. For example, 
qqq-yyyy results in a string of the form exemplified by 
Qtr 1-2005.
The function returns a text string.