The frequency of your inputs is 1 Hz, or 2*pi radians per second
The phase lag is pi/10 radians, which corresponds to
pi/10*(1/(2*pi)) seconds. That is 5 sample points at your sampling frequency.
Look at c for c(101:110) which corresponds to lags 0 to 10. See that the maximum value occurs at lag 5, which corresonds to 0.05 seconds as expected.