Bonjour,
Alors, si tu veux rajouter 7 jours à chaque clique:
function UpdateDates() {
var ss = SpreadsheetApp.getActiveSpreadsheet();
var sheet = ss.getActiveSheet();
//Get the dates from the cell and convert them into Milliseconds since 1970/01/01
var First = new Date(ss.getRange('A5').getValue()).getTime();
var dayInMs = 24*60*60*1000 //one day in Milliseconds //add sevendays to each date in milliseconds
First = First + (7*dayInMs)
//Convert Milliseconds to date use new Date(time in ms) and set Values of the cell
ss.getRange('A5').setValue(new Date(First));
}
Pour retirer 7 jours, la même chose avec First = First - (7*dayInMs)
Cordialement,
Fil.