Running system command fails but the same command works executed directly in bash

I am running the following code in perl

my $exp_date = `date --date="$(openssl x509 -enddate -noout -in certificate.pem | cut -d= -f 2)"  --iso-8601`; 

and I get:

date: invalid date ‘100 100 537 539 847 6210 70720 7….

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The exact command run in the command line

date --date="$(openssl x509 -enddate -noout -in certificate.pem | cut -d= -f 2)"  --iso-8601

prints the actual date in iso8601.

What am I doing wrong when running it in Perl?

>Solution :

The Perl special variable $( (see the documentation) contains the real group id of the process. Backticks interpolate variables. To prevent interpolation, escape the dollar sign by a backslash:

my $exp_date = `date --date="\$(openssl x509 -enddate -noout -in certificate.pem | cut -d= -f 2)"  --iso-8601`;
#                            ~