I just update in main.py file of controller of Web module. You can do this in inherit the main.py file.

Import below package in main.py

from dateutil.parser import parse
import datetime
import pytz

-->Update in CSVExport class for CSV. Add below code in this class.

def check_date(self, value):
        try:
            parse_data = parse(value)
            return parse_data
        except Exception as e:
            return False

Update from_data() function like below code.

def from_data(self, fields, rows):
        fp = io.BytesIO()
        writer = pycompat.csv_writer(fp, quoting=1)
        writer.writerow(fields)
        for data in rows:
                row = []
                for d in data:
                        if isinstance(d, pycompat.string_types) and d.startswith(('=', '-', '+')):
                                d = "'" + d
                        if type(d) is str:
                                parse_data = self.check_date(d)
                                if parse_data:
                                        if len(d) > 10:
                                                tz = pytz.timezone(request._context.get('tz'))
                                                d = (pytz.utc.localize(datetime.datetime.strptime(d,'%Y-%m-%d %H:%M:%S')).astimezone(tz)).strftime('%Y-%m-%d %H:%M:%S')

                        row.append(pycompat.to_text(d))
                writer.writerow(row)
        return fp.getvalue()

-->For Excel Update below code in ExcelExportV class in datetime condition.

elif isinstance(cell_value, datetime.datetime):
        tz = pytz.timezone(request._context.get('tz'))
        cell_value = (pytz.utc.localize(cell_value).astimezone(tz)).strftime('%Y-%m-%d %H:%M:%S')
        cell_style = datetime_style

After that, restart your odoo service and check.