Which function is used for rounding datetime expressions to a specified time interval?

The function used for rounding datetime expressions to a specified time interval is TIMEBUCKET. This function allows users to aggregate datetime values within specified time buckets, such as hours, days, weeks, etc. This is particularly useful in scenarios where analysis or reporting requires data to be grouped or rounded to certain intervals for more straightforward interpretation and visualization.

For instance, if you have a series of timestamps and you want to analyze the amount of sales per hour, using TIMEBUCKET can help you consolidate those individual timestamps into hourly intervals, making it easier to perform calculations like totals or averages over those periods.

In contrast, the other options do not serve the purpose of rounding datetime values to specified intervals. TIMEVALUE is intended for extracting the time portion from a datetime value, RIGHT is used for string manipulation, specifically to extract a specified number of characters from the right side of a string, and REPLACE is used to replace occurrences of a specified string within another string. Therefore, TIMEBUCKET is the best choice for the function that rounds datetime expressions effectively.