In this study, we use the light curves of significant number (more than 200) of supernovae of type Ia to calculate the value of the Hubble constant. After correcting these curves for their redshifts, we measure the time intervals for which their brightness decreases by 2 and 3 magnitudes from the peak value. We confirm the linear correlation between the relative value of this time interval (s-factor) and the absolute magnitude at the maximum of their brightness Mpeak. Using the obtained relation, we calculate the luminosity distances and the proper distances to the galaxies, hosting those supernovae. Having independently measured redshifts z, we calculate the receding speeds of each supernovae. Based on that we calculate the value of the Hubble constant H0 and the Hubble time tH.