The SNLS dataset must be supplemented with a set of nearby type Ia, supernovae at redshifts z~0.05 in order to obtain good constraints on the, cosmological parameters. These nearby SNe~Ia light curves are calibrated, in the Vega-based Landolt %24UBVRI%24 system. I will describe the procedure, used to align the SNLS lightcurves on the Landolt system. The, determination of the effective Megacam %24griz%24 passbands will also be, discussed. Finally, I will list the remaining uncertainties associated, with the calibration, and describe actions to be taken to decrease our, calibration-related systematic error budget.