Change language for bootstrap DateTimePicker

i think you have to set it in the options:

$(".form_datetime").datetimepicker({
    isRTL: false,
    format: 'dd.mm.yyyy hh:ii',
    autoclose:true,
    language: 'ru'
});

if its not working, be sure that:

$.fn.datetimepicker.dates['en'] = {
    days: ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"],
    daysShort: ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"],
    daysMin: ["Su", "Mo", "Tu", "We", "Th", "Fr", "Sa", "Su"],
    months: ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"],
    monthsShort: ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"],
    today: "Today"
};

is defined for 'ru'

If you use moment.js the you need to load moment-with-locales.min.js not moment.min.js. Otherwise, your locale: 'ru' will not work.