[R] splitting a long dataframe

[Swagath]

Dear all...Merry Christmas

I would like to split a long dataframe. The dataframe looks like this

x<-c('0:00:00', '0:30:00', '1:00:00', '1:30:00', '2:00:00', '2:30:00', 
'3:00:00', '0:00:00', '0:30:00', '1:00:00', '1:30:00', '2:00:00', 
'2:30:00', '3:00:00', '3:30:00', '4:00:00','0:00:00', '0:30:00', 
'1:00:00', '1:30:00', '2:00:00', '2:30:00', '3:00:00', '0:00:00', 
'0:30:00', '1:00:00', '1:30:00', '2:00:00', '2:30:00', '3:00:00' , 
'3:30:00', '4:00:00')

y=seq(1:32)

data1=data.frame(x,y)

i want to split in such a way that the output looks like

0:00:00  1  8 17 24
0:30:00  2  9 18 25
1:00:00  3 10 19 26
1:30:00  4 11 20 27
2:00:00  5 12 21 28
2:30:00  6 13 22 29
3:00:00  7 14 23 30
3:30:00 NA 15 NA 31
4:00:00 NA 16 NA 32

any ideas or functions that i look into for doing this?
Thanks a lot for your help and time.

Cheers,
Swagath