>function FirstDayOfMonth > lpar tdVar > local lcWasDateFormat, llWasCentury, lcReturn > assert vartype(tdVar) = 'D' > > lcWasDateFormat = set('date') > llWasCenturyOn = set('century') = 'ON' > set century on <b> set date to DMY</b> > > lcReturn = transform(tdVar - day(tdVar) + 1, '@D') > > set date to &lcWasDateFormat > if not llWasCenturyOn > set century off > endif > return lcReturn >endfunc >>