OK if I lookup Jan 5 {vlookup(jan 5, a1:b4, 2)} returns 2 since the function
returns the next largest value that is less than lookup_value. How do I get
the value for the next smallest value that is greater than the lookup_value?
In example below that would be 6 not 2.

Jan 1 2
Jan 7 6
Jan 13 0
Jan 15 8

Thanks.