As has been mentioned in similar issues already, it is not possible to always correctly infer that a particular string is a "datetime format" string. E.g.:

dt_format = 'The date is: %Y%m%d'
# format output
dt_out = datetime.strftime(datetime.now(), dt_format)

# parse input
my_datetime = datetime.strptime('The date is: 20180719', dt_format)

If the code is yours, you can choose to use r'%Y%m%d' or R'%Y%m%d' to avoid format highlighting. Note that r'...' will be highlighted as if it were a regex string, while R'...' is a raw string with no frills.

Additionally, the issue #106 has a proposal that would allow configuring the color scheme to hide %-formatting completely (implemented and being reviewed as of this writing).