"earliest = -1mon" in eventgen.conf not working in January month [Eventgen 7.0.0]

[mzadafiya-splunk]

Describe the bug
Below stanza in eventgen.conf is stopped working since Jan 2021 in Eventgen v7.0.0. Before Jan 2021 it was working fine.

[aws_billing_detailed_planner.sample]
outputMode = splunkstream
count = -1
end = 1
earliest = -1mon
latest = -1mon
index = main
sourcetype = aws:billing
source = s3://aws-billing-detailed-line-items-with-resources-and-tags-2017-11.csv.zip

It gives an error in splunkd.log. sharing piece of error here

01-06-2021 07:48:34.401 +0000 ERROR ExecProcessor - message from "/opt/splunk/bin/python3.7 /opt/splunk/etc/apps/SA-Eventgen/bin/modinput_eventgen.py" 2021-01-06 07:48:34 eventgen        ERROR    MainProcess Cannot parse relative time string
01-06-2021 07:48:34.402 +0000 ERROR ExecProcessor - message from "/opt/splunk/bin/python3.7 /opt/splunk/etc/apps/SA-Eventgen/bin/modinput_eventgen.py" 2021-01-06 07:48:34 eventgen        ERROR    MainProcess unsupported operand type(s) for -: 'datetime.datetime' and 'bool'
01-06-2021 07:48:34.402 +0000 ERROR ExecProcessor - message from "/opt/splunk/bin/python3.7 /opt/splunk/etc/apps/SA-Eventgen/bin/modinput_eventgen.py" Traceback (most recent call last):
01-06-2021 07:48:34.402 +0000 ERROR ExecProcessor - message from "/opt/splunk/bin/python3.7 /opt/splunk/etc/apps/SA-Eventgen/bin/modinput_eventgen.py"   File "/opt/splunk/etc/apps/SA-Eventgen/lib/splunk_eventgen/eventgen_core.py", line 259, in _worker_do_work
01-06-2021 07:48:34.402 +0000 ERROR ExecProcessor - message from "/opt/splunk/bin/python3.7 /opt/splunk/etc/apps/SA-Eventgen/bin/modinput_eventgen.py"     item.run()
01-06-2021 07:48:34.402 +0000 ERROR ExecProcessor - message from "/opt/splunk/bin/python3.7 /opt/splunk/etc/apps/SA-Eventgen/bin/modinput_eventgen.py"   File "/opt/splunk/etc/apps/SA-Eventgen/lib/splunk_eventgen/lib/eventgentimer.py", line 84, in run
01-06-2021 07:48:34.402 +0000 ERROR ExecProcessor - message from "/opt/splunk/bin/python3.7 /opt/splunk/etc/apps/SA-Eventgen/bin/modinput_eventgen.py"     self.real_run()
01-06-2021 07:48:34.402 +0000 ERROR ExecProcessor - message from "/opt/splunk/bin/python3.7 /opt/splunk/etc/apps/SA-Eventgen/bin/modinput_eventgen.py"   File "/opt/splunk/etc/apps/SA-Eventgen/lib/splunk_eventgen/lib/eventgentimer.py", line 170, in real_run
01-06-2021 07:48:34.402 +0000 ERROR ExecProcessor - message from "/opt/splunk/bin/python3.7 /opt/splunk/etc/apps/SA-Eventgen/bin/modinput_eventgen.py"     et = self.sample.earliestTime()
01-06-2021 07:48:34.402 +0000 ERROR ExecProcessor - message from "/opt/splunk/bin/python3.7 /opt/splunk/etc/apps/SA-Eventgen/bin/modinput_eventgen.py"   File "/opt/splunk/etc/apps/SA-Eventgen/lib/splunk_eventgen/lib/eventgensamples.py", line 270, in earliestTime
01-06-2021 07:48:34.402 +0000 ERROR ExecProcessor - message from "/opt/splunk/bin/python3.7 /opt/splunk/etc/apps/SA-Eventgen/bin/modinput_eventgen.py"     temptd = self.now(realnow=True) - tempearliest
01-06-2021 07:48:34.402 +0000 ERROR ExecProcessor - message from "/opt/splunk/bin/python3.7 /opt/splunk/etc/apps/SA-Eventgen/bin/modinput_eventgen.py" TypeError: unsupported operand type(s) for -: 'datetime.datetime' and 'bool'

We have tested various scenarios by changing machine DateTime to February and March 2021 and earliest/latest time to -31d and -2mon.
Only this error being generated for the scenario: Machine time in Jan 2021 and earliest\latest "-1mon".

To Reproduce
Steps to reproduce the behavior:

1. Install Splunk 8.1.1
2. Install Eventgen 7.0.0
3. Place eventgen.conf(Content added below) under $SPLUNK_HOME$/etc/apps/search/default/
4. Place issue-reproduce.sample(Content added below) under $SPLUNK_HOME$/etc/apps/search/samples/
5. Restart Splunk
6. Enable Eventgen modular Input
7. Open search and search "index=main" string in time range "All time"

Expected behavior
The event placed under issue-reproduce.sample file should be indexed in the main index.

Actual behavior
The event is not indexed. Error is being reported in the splunkd.log(log snippet mentioned above)

Screenshots
If applicable, add screenshots to help explain your problem.

Sample files and eventgen.conf file

Please attach your sample files and eventgen conf file
eventgen.conf

[global]
debug = false
verbose = false
outputMode = splunkstream
splunkHost = localhost
splunkUser = admin
splunkPass = admin
host = eventgen-hod
randomizeEvents = false
index = main
maxIntervalsBeforeFlush = 1

[issue-reproduce.sample]
outputMode = splunkstream
earliest = -1mon
latest = -1mon
index = main
sourcetype = test
source = test

issue-reproduce.sample

Test line to be indexed

Do you run eventgen with SA-eventgen?
Yes

If you are using SA-Eventgen with Splunk (please complete the following information):

• OS: Centos 7.6
• Browser: chrome
• Eventgen Version: 7.0.0
• Splunk Version: 8.1.1
• What other apps you have installed in Splunk etc/apps? It reproducible without any other app installed in Splunk

Additional context
We have tried to reproduce the same scenario in Eventgen 7.2.0. We got the same error in eventgen.log