import pandas
import datetime

def dateparse(time_in_secs):
    return datetime.datetime.fromtimestamp(float(time_in_secs))
x = pandas.read_csv('data.csv', delimiter=';', parse_dates=True,
    date_parser=dateparse, index_col='DateTime', names=['DateTime', 'X'],
    header=None)
out = x.truncate(before=datetime.datetime(2015, 12, 2, 12, 2, 18))
Чтение csv со столбцом метки времени с пандами