Sencha does not have this component, but something like this we get
Ext.define('Ext.form.field.Month', { extend: 'Ext.form.field.Date', alias: 'widget.monthfield', requires: ['Ext.picker.Month'], alternateClassName: ['Ext.form.MonthField', 'Ext.form.Month'], selectMonth: null, createPicker: function() { var me = this, format = Ext.String.format; return Ext.create('Ext.picker.Month', { pickerField: me, ownerCt: me.ownerCt, renderTo: document.body, floating: true, hidden: true, focusOnShow: true, minDate: me.minValue, maxDate: me.maxValue, disabledDatesRE: me.disabledDatesRE, disabledDatesText: me.disabledDatesText, disabledDays: me.disabledDays, disabledDaysText: me.disabledDaysText, format: me.format, showToday: me.showToday, startDay: me.startDay, minText: format(me.minText, me.formatDate(me.minValue)), maxText: format(me.maxText, me.formatDate(me.maxValue)), listeners: { select: { scope: me, fn: me.onSelect }, monthdblclick: { scope: me, fn: me.onOKClick }, yeardblclick: { scope: me, fn: me.onOKClick }, OkClick: { scope: me, fn: me.onOKClick }, CancelClick: { scope: me, fn: me.onCancelClick } }, keyNavConfig: { esc: function() { me.collapse(); } } }); }, onCancelClick: function() { var me = this; me.selectMonth = null; me.collapse(); }, onOKClick: function() { var me = this; if (me.selectMonth) { me.setValue(me.selectMonth); me.fireEvent('select', me, me.selectMonth); } me.collapse(); }, onSelect: function(m, d) { var me = this; me.selectMonth = new Date((d[0] + 1) + '/1/' + d[1]); } });
...
Ext.create('Ext.form.field.Month', { format: 'F, Y', renderTo: Ext.getBody() });
Script example