nearestTimeandID: Merge data frames based on the nearest datetime differences and an ID column. Also removes duplicate column names from the result.
Description
Takes two data frames each with time/date columns in date-time or date format (i.e., able to be compared using the function difftime), finds the rows of df2 that minimize the absolute value of the datetime for each of the rows in df1, and merges the corresponding rows of df2 into df1 for downstream processing.