Basically, what I’m trying to do is detect the days inside a .CSV file, and once these days have been extracted, display hour by hour OR from a specific hour to another hour.

What i did for extracting Date Days was:

import pandas
from tkinter import filedialog as ASK
from tkinter import messagebox
import datetime as dt
from matplotlib.figure import Figure
import matplotlib.pyplot as plt
import matplotlib.dates as mdates


class Presion:
def __init__(self):
    self.Doc1 = None
    self.Doc2 = None

    self.excel1 = None
    self.excel2 = None

    self.DiasDisponibles1 = None
    self.DiasDisponibles2 = None

    self.DayList1 = []
    self.DayList2 = []

    self.Plot1X = []
    self.Plot1Y = []

    self.Plot2X = []
    self.Plot2Y = []

    self.DayEndsValue1 = []
    self.DayEndsValue2 = []
    pass


def ReadPresion1(self):
    self.Doc1 = ASK.askopenfilename(initialdir=" /", title="SELECT .CSV FILE!!", filetypes=(("files", "*.csv"), ("all files", "*.*")))

    try:
        self.excel1 = pandas.read_csv(self.Doc1, sep="t", encoding="utf-16")
    except FileNotFoundError:
        messagebox.showerror(title="INVALID!", message="Make sure select .CSV FILES!")
    else:
        self.excel1.fillna(0, inplace=True)
        self.excel1.columns = ["Hour", "Date", "Value"]

        Last_Date = None
        DayEnds = 0

        for Date in self.excel1.loc[:,"Date"]:
            DayEnds += 1
            if Date != Last_Date:
                self.DayList1.append(Date)
                self.DayEndsValue1.append(DayEnds)
            Last_Date = Date

        self.DayEndsValue1.append(DayEnds)
        print(self.DayList1)
        print(self.DayEndsValue1)

        for Hour in range(self.DayEndsValue1[0], self.DayEndsValue1[1]):
            ValueX = self.excel1.loc[Hour, "Hour"]
            self.Plot1X.append(ValueX)

        for Value in range(self.DayEndsValue1[0], self.DayEndsValue1[1]):
            ValueY = self.excel1.loc[Value, "Value"]
            self.Plot1Y.append(ValueY)



        # Figura1Presion = Figure(figsize=(7,6), dpi=100)
        # Figura1Presion.add_subplot(111).plot(self.Plot1X, self.Plot1Y)
        Figura1ASDF = plt.figure(figsize=(12,7))
        Figura1ASDF.add_subplot(111).plot(self.Plot1X, self.Plot1Y)



        locator = mdates.AutoDateLocator(minticks=12, maxticks=24)
        plt.gcf().axes[0].xaxis.set_major_locator(locator)
        plt.xticks(rotation=45)
        plt.gcf().autofmt_xdate()




        return Figura1ASDF



def getDaysP1(self):
    return self.DayList1

and then in my main script i have a set up tkinter program running where i set up some button to ask .CSV file, etc
Here some functionallity:

def showPlotPresion1():
Figure1 = OBJ_PRESION.ReadPresion1()

DaysP1 = OBJ_PRESION.getDaysP1()
showDaysPresion1(DaysP1)

canvas = FigureCanvasTkAgg(Figure1, master=WindowPresion)  # A tk.DrawingArea.
canvas.draw()
canvas.get_tk_widget().pack(side=TOP, fill=BOTH, expand=1)

toolbar = NavigationToolbar2Tk(canvas, WindowPresion)
toolbar.update()
canvas.get_tk_widget().pack(side=TOP, fill=BOTH, expand=1)


def showDaysPresion1(ListPresion1):

optionsSelect = StringVar()
optionsSelect.set("04/26/2021")

TextP1 = Label(WindowPresion, text="Dias Disponibles Presion 1 -->")
TextP1.pack(anchor="w", side=LEFT)

List1 = OptionMenu(WindowPresion, optionsSelect, *ListPresion1)
List1.pack(anchor="w", side=LEFT)

How do I extract available hours from these read-through days?

Here is the VSC format:
CSV FILE