KivyMD DatePicker save multiple dates

I want that you can add and choose multiple dates. I tried to send a number with the button click button_nr but I don’t know how I can pass it to the on_save function, so that I can change the self.ids.date_label(button_nr).text . If somebody has a better idea how to save multiple dates I’m open for suggestions. Thank you

def on_save(self, instance, value, date_range):
    date_value = datetime.datetime.strptime(str(value), "%Y-%m-%d")
    date_value_eu = date_value.strftime("%d.%m.%Y")
    self.ids.date_label1.text = str(date_value_eu)

def show_date_picker(self, button_nr):
    print(button_nr)
    date_dialog = MDDatePicker()
    date_dialog.bind(on_save=self.on_save, on_cancel=self.on_cancel)
    date_dialog.open()

The kv file part

MDRaisedButton:
        on_release: root.show_date_picker(1)

Answer

You can use my code, I have designed this app in order to have a recycleview plus a search bar, the recycle list item in this example is moved into the pick date function and it changes the text of the list item widget (check the picture), here is the code by jbsidis (I am posting this after I commented your question):

from kivymd.app import MDApp
from kivy.lang.builder import Builder
from kivy.core.window import Window
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.floatlayout import FloatLayout
from kivymd.uix.list import OneLineIconListItem

from kivy.properties import (
    StringProperty,
    BooleanProperty,
    ObjectProperty,
    NumericProperty,
    ListProperty,
    OptionProperty,
)
Window.size = (330, 660)


kv = '''
#:import MDTextField kivymd.uix.textfield.MDTextField
<MyTile@SmartTileWithLabel>
    size_hint_y: None
    height: "240dp"

<S>:
    MDTextFieldRound:
        pos_hint: {"center_x": .5, "center_y": .95}
        normal_color : [1,1,1,.1]
        color_active : [1,1,1,1]
        size_hint: .8, .07
        hint_text : 'Search a product...'
        icon_left : 'magnify'



<JBSIDIS>
    on_release: app.show_date_picker(root)
    IconLeftWidget:
        icon: "Photos/pro.jpg"

Screen:
    name: "pantalla1"
    MDToolbar:
        id: tb1
        title: "jbsidis"
        pos_hint: {"top": 1}
        md_bg_color: (.1, .1, .5, 1)

    GridLayout:
        cols: 2
        padding: dp(20)
        FloatLayout:
            MDTextFieldRound:
                id: search_field
                pos_hint: {"center_x": .5, "center_y": .87}
                hint_text : 'jbsidis...'
                icon_left : 'magnify'
                normal_color : (100, 100, 50, .5)
                color_active : (255, 255, 255, 0)
                on_text: app.search(root.ids.rvvv9,self.text)

    BoxLayout:
        id: m5
        spacing: dp(10)
        #padding: dp(20)
        pos_hint: {"center_x": .5, "center_y": .32}
        orientation: "vertical"
        BoxLayout:
            id: s_res9
            size_hint_y: None
            height: self.minimum_height
            pos_hint: {"center_x": .5, "center_y": .4}
            orientation: "vertical"
        RecycleView:
            id: rvvv9
            key_viewclass: 'viewclass'
            key_size: 'height'
            RecycleBoxLayout:
                padding: dp(10)
                spacing: dp(5)
                default_size: None, dp(75)
                default_size_hint: 1, None
                size_hint_y: None
                height: self.minimum_height
                orientation: 'vertical'

    MDToolbar:
        id: success_screen_toolbar
        title: "jbsidis"
        pos_hint: {"top": 1}
        right_action_items: [["progress-check", lambda: print(6)]]


    MDBottomAppBar:
        MDToolbar:
            id: success_screen_bottomappbar
            icon: "magnify"
            on_action_button: app.eq(root.ids.search_field,True)
            type: 'bottom'
            mode: 'center'
            #elevation: '8dp'
            left_action_items: [["calendar-text", lambda x: print(6)], ["account-group", lambda x: print(6)]]
            right_action_items: [["magnify", lambda x: app.eq(root.ids.search_field,True)], ["menu", lambda x: print(6)]]

'''
authors="jbsidis"
class JBSIDIS(OneLineIconListItem):
    datex=StringProperty()
    pass
class blanks1(BoxLayout):
    pass
class S(FloatLayout):
    pass

authors4="jbsidis"
books="""
Austen, Jane (72159) jbsidis
Du Bois, W. E. B. (William Edward Burghardt) (7364) jbsidis
Stowe, Harriet Beecher (7362) jbsidis
Vatsyayana (7343) jbsidis
Schopenhauer, Arthur (7317) jbsidis
Foote, Mary Hallock (7308) jbsidis
Bhide, Shivaram Parashuram (7256) jbsidis
Indrajit, Bhagavanlal (7256) jbsidis
"""
import time
import datetime
class Main(MDApp):
    def build(self):
        self.theme_cls.primary_palette = "Green"
        return Builder.load_string(kv)
    def get_date(self, date):
        print(date)
        t=str(date).split("-")
        text="[b]"+str(t[-1])+"/"+str(t[1])+"/"+str(t[0])

        year=time.strftime("%Y")
        mes=time.strftime("%m")
        dia=time.strftime("%d")

        bx.text=text
        afecha=str(t[-1])+"/"+str(t[1])+"/"+str(t[0])
                            
        return date
    def show_date_picker(self,b):
        from kivymd.uix.picker import MDDatePicker
        global bx
        bx=b

        yearx=time.strftime("%Y")
        mes=time.strftime("%m")
        dia=time.strftime("%d")

        current=time.strftime("%Y:%m:%d")

        min_date = datetime.datetime.strptime(current, '%Y:%m:%d').date()
        date_dialog = MDDatePicker(
            callback=self.get_date,
            min_date=min_date
            )
        date_dialog.open()

    def all_pdfs(self):
        return books.splitlines()
    def eq(self,a,b):
        a.focus=True
    def search(self,a,b):
        a.data=[]
        for x in self.all_pdfs():
            if b in str(x):
                a.data.append(
                {
                    "viewclass": "JBSIDIS",
                    "markup": True,
                    "text": "[b][size=33]jbsidis: [/b][/size]"+str(x)
                }
                    )
        pass


Main().run()

This is one of many ways you can do things using kivy and kivymd, jbsidis, everything is possible with Python and Kivy, here is the image, greetings from El Salvador: