Calendar.py

# parhamTheDeveloper
from PyQt5 import QtCore, QtGui, QtWidgets


class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(411, 241)
        MainWindow.setMinimumSize(QtCore.QSize(411, 241))
        MainWindow.setMaximumSize(QtCore.QSize(411, 241))
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.calendarWidget = QtWidgets.QCalendarWidget(self.centralwidget)
        self.calendarWidget.setGeometry(QtCore.QRect(0, 0, 411, 241))
        font = QtGui.QFont()
        font.setFamily("Tahoma")
        font.setPointSize(15)
        self.calendarWidget.setFont(font)
        self.calendarWidget.setSelectedDate(QtCore.QDate(self.year(), self.month(), self.day()))
        self.calendarWidget.setGridVisible(False)
        self.calendarWidget.setSelectionMode(QtWidgets.QCalendarWidget.SingleSelection)
        self.calendarWidget.setHorizontalHeaderFormat(QtWidgets.QCalendarWidget.ShortDayNames)
        self.calendarWidget.setVerticalHeaderFormat(QtWidgets.QCalendarWidget.ISOWeekNumbers)
        self.calendarWidget.setNavigationBarVisible(True)
        self.calendarWidget.setDateEditEnabled(True)
        self.calendarWidget.setDateEditAcceptDelay(1500)
        self.calendarWidget.setObjectName("calendarWidget")
        MainWindow.setCentralWidget(self.centralwidget)

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)
        
    def year(self):
        import datetime
        return datetime.datetime.today().year

    def month(self):
        import datetime
        return datetime.datetime.today().month    

    def day(self):
        import datetime
        return datetime.datetime.today().day 

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "Calendar"))


if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    MainWindow = QtWidgets.QMainWindow()
    ui = Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())