How to correct this issue with rectangularPulse funtion?

This is my first time posting and I am slightly new to using Matlab. I am currently trying to create a rectangular waveform which goes from 0 to 4T0, and I am having an issue with the rectangular pulse function starting and ending at 0.5 instead of 0. Am I doing something incorrectly? My code is posted below:

T0 = 1; fs = 16; A = 1;

ts = 16;

t = 0:T0/(ts-1/ts):4*T0;

n = 16; %fft with padding to make the vector length equal to 1024

S1 = rectangularPulse((t - (T0/2))/T0);

S2 = rectangularPulse((t - (3*T0/2))/T0);

S3 = rectangularPulse((t - (5*T0/2))/T0);

S4 = rectangularPulse((t - (7*T0/2))/T0);

xt = A*T0*(S1-S2+S3-S4);

figure;plot(t,xt);