function bisesti(an)
{
bis=fint(an/4)
if (an==bis*4) {
	bise=1
	psec=fint(an/100)
	quat=fint(an/400)
	if (an==psec*100 && an!=quat*400) bise=0
}
else {
	bise=0
}
return bise
}

function formattaData(adesso,datac)  {
if (datac) {
	prod=datac.split("-")
	gg=1*prod[0]
	mm=1*prod[1]
	aaaa=1*prod[2]
	bst=bisesti(aaaa)
	mese[2] = (bst==1)? 29:28
	if (mm<1 || !mm || mm>12) mm=adesso.getMonth()+1;
	if (gg<1 || !gg || gg>mese[mm]) gg=adesso.getDate();
	if (aaaa<1 || !aaaa) aaaa=adesso.getFullYear();
	}
else {
	gg=adesso.getDate() 
	mm=adesso.getMonth()+1
	aaaa=adesso.getFullYear()
}
hh=adesso.getHours()
}


function fneffe(x) {
x=1*x
f=Math.sqrt((x+1)/(1-x))
return f
}

function fnrp(x) {
x=1*x
f=x-2*pig*fint(x/(2*pig))
return f
}

function tempano(eccp,tsp)
{
dif=1
E0=1
while(dif>0.000006) {
E1=E0-(E0-eccp*Math.sin(E0)-tsp)/(1-eccp*Math.cos(E0))
dif=Math.abs(E1-E0)
E0=E1
}

ef=fneffe(eccp)
tetasp=2*Math.atan(ef*Math.tan(E1/2))
teta=fnrp(tetasp)
return teta
}



function giulia(gg,mm,aa,hh,mese)   {
bises=bisesti(aa)
sommese=0
if (mm>1) {
	for (i=1;i<mm;i++) {
 		sommese=sommese+mese[i]
	}
}
gina=gg+sommese-bises*(mm>2)
aro=aa-1953
nabi=fint(aro/4)
MJD=1096+aro*365+nabi+gina
MJD=((MJD-1)*24+hh)/24
JD=MJD+2433282.5
}


function trovadat(gi,me,an,mese) {
bst=bisesti(an)
mese[2] = (bst==1)? 29:28

if (gi>mese[me]) {
	gi=gi-mese[me]
	if (me<12) {
	me++
	}
	else {
    me=1
	an++
	}
}
if (gi<1) {
	if (me>1) { 
		me--
	}
	else {
		me=12
		an--
	}

 gi=mese[me]+gi
 }

document.sistema.time.value=gi+"-"+me+"-"+an

gg=gi
mm=me
aaaa=an

}