Date
dateAdd(dateAdd(fromTimestamp(-6.2107516725e+13), toNumber(prop("Year")) - 1, "years"), if(day(dateAdd(fromTimestamp(-6.2107516725e+13), toNumber(prop("Year")) - 1, "years")) <= 4, 4 - day(dateAdd(fromTimestamp(-6.2107516725e+13), toNumber(prop("Year")) - 1, "years")), if(day(dateAdd(fromTimestamp(-6.2107516725e+13), toNumber(prop("Year")) - 1, "years")) == 5, 6, 5)), "days")
Uses November 22, 0001’s timestamp (
-6.2107516725e+13) as the base date, adds the selected number of years minus 1, and then the additional number of days based on where the 22nd falls in the week of that year.Formatted
if(empty(prop("Year")), "", "Thanksgiving" + if(prop("Date") > now(), " will be on", " was on") + formatDate(prop("Date"), " [the] Do [of] MMMM"))
Combined
if(empty(prop("Year")), "", "Thanksgiving" + if(dateAdd(dateAdd(fromTimestamp(-6.2107516725e+13), toNumber(prop("Year")) - 1, "years"), if(day(dateAdd(fromTimestamp(-6.2107516725e+13), toNumber(prop("Year")) - 1, "years")) <= 4, 4 - day(dateAdd(fromTimestamp(-6.2107516725e+13), toNumber(prop("Year")) - 1, "years")), if(day(dateAdd(fromTimestamp(-6.2107516725e+13), toNumber(prop("Year")) - 1, "years")) == 5, 6, 5)), "days") > now(), " will be on", " was on") + formatDate(dateAdd(dateAdd(fromTimestamp(-6.2107516725e+13), toNumber(prop("Year")) - 1, "years"), if(day(dateAdd(fromTimestamp(-6.2107516725e+13), toNumber(prop("Year")) - 1, "years")) <= 4, 4 - day(dateAdd(fromTimestamp(-6.2107516725e+13), toNumber(prop("Year")) - 1, "years")), if(day(dateAdd(fromTimestamp(-6.2107516725e+13), toNumber(prop("Year")) - 1, "years")) == 5, 6, 5)), "days"), " [the] Do [of] MMMM"))