multiple ifelse statements - r

Question

I am attempting to assign values to a column based on conditional statements but the POSIXct format seems to be throwing me off. I have a column of times and would like to assign them to day/night/dawn/dusk with something like this:
if(t40636$time>t40636$dawn.b&t40636$time<t40636$dawn.e){
t40636$time.periods=1
} else {
if(t40636$time>t40636$mid.day.b&t40636$time<t40636$mid.day.e){
t40636$time.periods=2
} else {
if(t40636$time>t40636$dusk.b&t40636$time<t40636$dusk.e){
t40636$time.periods=3
} else {
if(t40636$time>t40636$mid.night.b&t40636$time<t40636$mid.night.e){
t40636$time.periods=4
} else {
t40636$time.periods=0
}
}
}
}
However, this code does not work because of the format of the columns and yields the matrix seen below (only 0s in the time.periods column).
Date Temp..ºC. Depth..m. Light time time.at.depth dawn.b dawn.e dusk.b
1 2012-06-19 14.47 -21.5 255 15:32 0 01:42 04:42 19:13
2 2012-06-19 16.99 -20.2 255 15:37 5 01:42 04:42 19:13
3 2012-06-19 12.60 -18.8 255 15:41 4 01:42 04:42 19:13
4 2012-06-19 16.36 -17.5 255 15:46 5 01:42 04:42 19:13
5 2012-06-19 16.36 -13.4 255 15:51 5 01:42 04:42 19:13
6 2012-06-19 17.94 -2.7 255 15:56 5 01:42 04:42 19:13
dusk.e mid.day.b mid.day.e mid.night.b mid.night.e time.periods
1 22:13 10:27 13:27 22:27 01:27 0
2 22:13 10:27 13:27 22:27 01:27 0
3 22:13 10:27 13:27 22:27 01:27 0
4 22:13 10:27 13:27 22:27 01:27 0
5 22:13 10:27 13:27 22:27 01:27 0
6 22:13 10:27 13:27 22:27 01:27 0
ifelse yields something close to what I want but I can't do multiple statements with it. Any suggestions are greatly appreciated.
t40636$time.periods=ifelse(t40636$time>t40636$dawn.b&t40636$time<t40636$dawn.e,1,0)

Answer 1

The answer to "fix my multiple if-else statements" is nearly always "Don't use multiple if-else constructions."
The R-language has a very nice switch function, and its help page has some excellent examples.