Create POSIX-compliant columns for dt components (e.g., year, hour, month)

Given a dataframe with either `utc_orig` or `UTC time` column, adds five more columns: year, month, day, hour minute.

create_time_cols(df)

Arguments

df	a dataframe with a timestamp column (`utc_orig` or `UTC time`)

Value

a dataframe with five additional time columns