Which function is used to return the first day of the month for a given date?

The function used to return the first day of the month for a given date is DATETRUNC. This function truncates a date to the specified date part, allowing you to focus on specific intervals, such as the month, year, or day. By utilizing DATETRUNC with the month as the specified part, it effectively removes the day component of the date, returning the first day of that month.

For instance, if you have a date like July 15, 2023, using DATETRUNC for the month would yield July 1, 2023. This capability makes DATETRUNC particularly useful in scenarios involving time series analysis or reporting, where understanding the start of the interval is critical.

In contrast, other functions mentioned do not fulfill this specific requirement. For example, DATEFROMPARTS is primarily used to create a date value from specified year, month, and day integers. DATE_BUCKET serves to group date values into defined buckets or intervals, typically for aggregation, rather than returning a specific date. DATEPART extracts a specific part of a date, like the year or month, but does not return a date representing the first day of the month. Hence, DATETRUNC is the right choice for obtaining