G'day JohnGG,

++ Upon reading the OP, I immediately thought of Time::Piece; then, after scrolling through the posts, I saw you'd used this already.

If I may, some minor improvements:

• Instead of decrementing $tp in two statements, you can do that in one: "$tp -= 2 * ONE_HOUR".
• Your output has a slightly different format to the OP's input: comma after day and introduced timezone. You can mostly fix that by using the same date format for the input and output.
  Update: On rereading, I also see the month name and day are swapped as are the time and year. The suggested fix handles both of those cases also.
• If the leading zero on the month nameday is a problem for the OP, you can fix that with sprintf. I added a "$tp += 6 * ONE_DAY" to test that.
  • Checking `man strptime` on my Cygwin platform, I see %d gives a two-digit string, padded with a zero for a single-digit month day. I couldn't find a format for that which doesn't pad with a zero. Assuming I didn't simply miss it, if one exists on another OS, it may not be portable.

Here's the updated code:

    my $date = q{Sat Jun  4 22:47:31 2022};
    my $fmt_t = q{%a %b %d %T %Y};
    my $fmt_s = q{%s %s %2d %s %d};
    my $tp = Time::Piece->strptime($date, $fmt_t);
    $tp -= 2 * ONE_HOUR;
    say sprintf $fmt_s, split q{ }, $tp->strftime($fmt_t);
    $tp += 6 * ONE_DAY;
    say sprintf $fmt_s, split q{ }, $tp->strftime($fmt_t);
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which outputs:

Sat Jun  4 20:47:31 2022
Fri Jun 10 20:47:31 2022
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