Python - pandas - filter by date and time

import pandas as pd

#
# Filter rows by strings with date and time.
# It will not work if date is in format 04-06-2018 .
#

text = '''
293  2018-06-14  14:55  1832.15  1833.40  1831.90  1833.35   37947
294  2018-06-14  15:00  1833.40  1834.95  1833.30  1834.90  106271
295  2018-06-14  15:05  1834.95  1835.05  1834.40  1834.85  102107
296  2018-06-14  15:10  1834.80  1834.85  1832.95  1833.80   95931
297  2018-06-14  15:15  1833.75  1834.85  1833.05  1834.85  124639
298  2018-06-14  15:20  1834.85  1834.85  1831.55  1832.50  121206
'''

data = [line.split() for line in text.split('\n') if line.strip()]

df = pd.DataFrame(data, columns=['index', 'Date','Time','open','high','low','close','volume'])
df.set_index('index')

d1 = '2018-06-14'
t1 = '15:00'
t2 = '15:15'

new_df = df[ (df["Date"] == d1) & (df["Time"] == t1) ]
print(new_df)

new_df = df[ (df["Date"] == d1) & (df["Time"] >= t1) & (df["Time"] <= t2) ]
print(new_df)
print(new_df["high"].max())