Я просматривал исходный код, и кажется, что он не поддерживает изменение первого дня недели, вот параметры, которые он поддерживает
fe.fn.datetimepicker.defaults = {
format: !1,
dayViewHeaderFormat: "MMMM YYYY",
extraFormats: !1,
stepping: 1,
minDate: !1,
maxDate: !1,
useCurrent: !0,
collapse: !0,
locale: pe.locale(),
defaultDate: !1,
disabledDates: !1,
enabledDates: !1,
icons: {
time: "glyphicon glyphicon-time",
date: "glyphicon glyphicon-calendar",
up: "glyphicon glyphicon-chevron-up",
down: "glyphicon glyphicon-chevron-down",
previous: "glyphicon glyphicon-chevron-left",
next: "glyphicon glyphicon-chevron-right",
today: "glyphicon glyphicon-screenshot",
clear: "glyphicon glyphicon-trash",
close: "glyphicon glyphicon-remove"
},
tooltips: {
today: "Go to today",
clear: "Clear selection",
close: "Close the picker",
selectMonth: "Select Month",
prevMonth: "Previous Month",
nextMonth: "Next Month",
selectYear: "Select Year",
prevYear: "Previous Year",
nextYear: "Next Year",
selectDecade: "Select Decade",
prevDecade: "Previous Decade",
nextDecade: "Next Decade",
prevCentury: "Previous Century",
nextCentury: "Next Century"
},
useStrict: !1,
sideBySide: !1,
daysOfWeekDisabled: !1,
calendarWeeks: !1,
viewMode: "days",
toolbarPlacement: "default",
showTodayButton: !1,
showClear: !1,
showClose: !1,
widgetPositioning: {
horizontal: "auto",
vertical: "auto"
},
widgetParent: null,
ignoreReadonly: !1,
keepOpen: !1,
focusOnShow: !0,
inline: !1,
keepInvalid: !1,
datepickerInput: ".datepickerinput",
keyBinds: {
up: function(e) {
if (e) {
var t = this.date() || pe();
e.find(".datepicker").is(":visible") ? this.date(t.clone().subtract(7, "d")) : this.date(t.clone().add(this.stepping(), "m"))
}
},
down: function(e) {
if (e) {
var t = this.date() || pe();
e.find(".datepicker").is(":visible") ? this.date(t.clone().add(7, "d")) : this.date(t.clone().subtract(this.stepping(), "m"))
} else
this.show()
},
"control up": function(e) {
if (e) {
var t = this.date() || pe();
e.find(".datepicker").is(":visible") ? this.date(t.clone().subtract(1, "y")) : this.date(t.clone().add(1, "h"))
}
},
"control down": function(e) {
if (e) {
var t = this.date() || pe();
e.find(".datepicker").is(":visible") ? this.date(t.clone().add(1, "y")) : this.date(t.clone().subtract(1, "h"))
}
},
left: function(e) {
if (e) {
var t = this.date() || pe();
e.find(".datepicker").is(":visible") && this.date(t.clone().subtract(1, "d"))
}
},
right: function(e) {
if (e) {
var t = this.date() || pe();
e.find(".datepicker").is(":visible") && this.date(t.clone().add(1, "d"))
}
},
pageUp: function(e) {
if (e) {
var t = this.date() || pe();
e.find(".datepicker").is(":visible") && this.date(t.clone().subtract(1, "M"))
}
},
pageDown: function(e) {
if (e) {
var t = this.date() || pe();
e.find(".datepicker").is(":visible") && this.date(t.clone().add(1, "M"))
}
},
enter: function() {
this.hide()
},
escape: function() {
this.hide()
},
"control space": function(e) {
e.find(".timepicker").is(":visible") && e.find('.btn[data-action="togglePeriod"]').click()
},
t: function() {
this.date(pe())
},
"delete": function() {
this.clear()
}
},
debug: !1,
allowInputToggle: !1,
disabledTimeIntervals: !1,
disabledHours: !1,
enabledHours: !1,
viewDate: !1
}
, и для локалей он, кажется, принимаетих, и вы можете использовать один из них здесь