We calculate the type Ia supernova rate for different star formation histories in galaxies by adopting the most popular and recent progenitor models .
We show that the timescale for the maximum in the type Ia supernova rate , which corresponds also to time of the maximum enrichment , is not unique but is a strong function of the adopted stellar lifetimes , initial mass function and star formation rate .
This timescale varies from \sim 40 - 50 Myr for an instantaneous starburst to \sim 0.3 Gyr for a typical elliptical galaxy to \sim 4.0 - 5.0 Gyr for a disk of a spiral Galaxy like the Milky Way .
We also show that the typical timescale of 1 Gyr , often quoted as the typical timescale for the type Ia supernovae , is just the time at which , in the solar neighbourhood , the Fe production from supernovae Ia starts to become important and not the time at which SNe Ia start to explode .
As a cosequence of this , a change in slope in the [ O/Fe ] ratio is expected in correspondance of this timescale .
We conclude that the suggested lack of supernovae Ia at low metallicities produces results at variance with the observed [ O/Fe ] vs. [ Fe/H ] relation in the solar region .
We also compute the supernova Ia rates for different galaxies as a function of redshift and predict an extended maximum between redshift z \sim 3.6 and z \sim 1.6 for elliptical galaxies , and two maxima , one at z \sim 3 and the other at z \sim 1 , for spiral galaxies , under the assumption that galaxies start forming stars at z _ { f } \sim 5 and \Omega _ { M } = 0.3 , \Omega _ { \Lambda } = 0.7 .