Got some info from the Strawberry folks {not the developers about fixing it, but someone else at cpan mentioning the problem}:
"tzset" is common Perl command which our MIDAS scheduling software utilizes when calculating times and time zones.

...

We understand that from around June 2010, tzset is no longer recognized or implemented in Strawberry Perl. We have no idea why this is the case, as there is very little information available from the developers of Strawberry Perl. It is unknown whether this is just a bug/glitch in Strawberry Perl, or if this common functionality has been permanently and intentionally removed.

I'm guessing that, since it is now a decade later and no tzset, that it has been permanently removed. I wonder if there's a workaround? tzset seems simple enough:
"tzset" This is identical to the C function "tzset()" for setting the current timezone based on the environment variable "TZ", to be used by "ctime()", "localtime()", "mktime()", and "strftime()" functions.
But what's amusing {perhaps} I can't find a man page for the C tzset() function on my system {Ubuntu 18.04.3}

In reply to Re^6: svg line graphs by BernieC
in thread svg line graphs by BernieC

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