Assume your data in column A looks like this:
(4 data cells and 2 blanks)
A B
May
jnrc
hapj
odgq
nmek

June
gqck
qfde
qicn
rmbp

July
mrki
apbr
kqak
ibkc

In column B, type May, select it and 5 blank cells below it,
and drag down the fill handle as far as data in column A goes.
Select data in column A and
Go To Special Blanks
Delete Shift cells left