angularjs - Firebase simple query date range ... doesn't work -

i have array keys :

['-ksh1rj8bgbowkdwdn0j', '-ksh0b8mfpcb2_zi8h3q', ...]; 

and each key, know if "ts_exp" expiration timestamp between yesterday , tomorrow both timestamps.

 var yesterday = moment().subtract(1, 'day').format("x");  var tomorrow = moment().add(1, 'day').format("x");   foreach(... key){         var rootref = firebase.database().ref('demandes').child(key)         .orderbychild('ts_exp')         .startat(yesterday)         .endat(tomorrow);          rootref.once("value", function(messagesnapshot) {           console.log(messagesnapshot.val()); // return null         });     } 

what's wrong query? this null (but have "demande" have "ts_exp" between 2 values). did .indexon "ts_exp" in firebase rules also.
thank
data structure :

 -demandes     ----- -ksh1rj8bgbowkdwdn0j     ---------- ts_exp : 14123123123,     ---------- title : "pipo1",     ---------- desc : "desc"     ----- -ksh0b8mfpcb2_zi8h3q     ---------- ts_exp : 14123176576,     ---------- title : "pipo2",     ---------- desc : "desc2" 

looks ts_exp values numbers (14123123123) startat / endat strings, , firebase database sorts numbers before strings, query searching range no data.

untested, try:

var yesterday = moment().subtract(1, 'day').valueof(); var tomorrow = moment().add(1, 'day').valueof();