If you have 100 simulations per day, and you want to use your simulations to estimate 2.5% to 97.5% around the median (a 95% confidence interval), you could rephrase that as the 2.5th percentile and 97.5th percentile of your simulations.
a = randn(100,44195);
botmedtop = prctile(a,[2.5 50 97.5]); % Lower CI, median, upper CI
plot(botmedtop') % note the transpose, plot will make one line per column and botmedtop is 3 x 44195
legend('Lower','Median','Upper')
