I would like to ask about swap zero curve calculation algorithm by Bloomberg terminal. This is a plain vanilla CZK interest rate swap, fixing the Prague IBOR. My task is to calculate zero rates from market rates, however I have only managed to get accurate zero rates from 2 years onwards. I tried to bootstrap spot rates from FRAs (CKFR0F1 is FRA 6x12 and CKFR011 is 12x18) with this formula:
$(1+r_{0;t_{0}}\frac{t_{0}}{360})*(1+r_{t_{0};t_{0}+t{u}}\frac{t_{u}}{360})= (1+r_{0;t_{0}+t{u}}\frac{t_{u}+t_{0}}{360})$
Where $r_{0;t_{0}}= 0.0056$, $r_{t_{0};t_{0}+t{u}} = 0.0095$, $t_{0}=182$ and $t_{u}=183$. By solving this equation I get $r_{0;t_{0}+t{u}}=r_{0;1}= 0.007568827$, which is off only by a tiny fraction. I guess the mistake will be in day count conventions, however this is the closest I have come to the correct solution. Can someone explain how the calculation should be done?
I have also attached screenshots of the swap yield curve and cash-flows.