How to convert decimal dates into date and time in excel

=LET(dec,A2,y,INT(dec),fr,dec-y,leap,DATE(y,12,31)-DATE(y,1,1)+1,ns,fr*(leap*86400),nd,INT(fr*leap),d,DATE(y,1,1)+nd,r,ROUND(ns-(nd*86400),0),h,INT(r/3600),m,INT((r-(h*3600))/60),s,INT(r-(h*3600)-(m*60)),d+TIME(h,m,s))