OK, yes, I see what you (Homero) are saying: we don't have a daylength estimate until we have already entered MTCLIM.  Now I need to double-check whether mtclim_data->s_srad[] is used inside MTCLIM if supplied by the user.  If so, then we have another bug to fix, since the same problem of units (W/m2 over entire day or daylight hours) will exist.