Convert float to timestamp pandas python

I use pandas python

import pandas as pd
filename = 'excel.xlsx'
my_sheets = pd.ExcelFile(filename)
all_sheets = my_sheets.sheet_names
df = pd.concat(pd.read_excel(filename, parse_dates=['Date'], sheet_name=[all_sheets[0]], 
df = df.replace(np.nan, 0, regex=True)
data= [tuple(x) for x in df.values]

When I replace Nan with zero, the date flies, example:

data = [(1.6102368e+18, 'Andre', 0),(1.6102368e+18, 0, 30),(1.6102368e+18, 0, 32)]

I need such data, example:

data = [(Timestamp('2021-01-10 00:00:00'), 'Andre', 0),(Timestamp('2021-01-10 00:00:00'), 0, 30),(Timestamp('2021-01-10 00:00:00'), 0, 32)]

I tried to change float to timestamp but gives error, I need to convert float to timestamp

for i in range(len(tuples)):
    date = datetime.datetime.fromtimestamp(tuples[i][0] / 1e3


just add df['Date'] = pd.to_datetime(df['Date']) to your code

df = df.replace(np.nan, 0, regex=True)
df['Date'] = pd.to_datetime(df['Date'])
data= [tuple(x) for x in df.values]