You're using the alt-ajax-dashboard.php (ajax-dashboard6.php) Version 6.95e - 01-Feb-2022 .. there's a 6.95f version which handles PHP 8.1.
The two errata are coming from the split_hash_date() function, and there are two instances of that:
Line 1165: <?php $_array = split_hash_date($dateoflastrainalways) ?>
Line 1734: <?php $_array = split_hash_date($firstsnowseason) ?>
Looking at testtags.php shows:
$dateoflastrainalways = '---';
and $firstsnowseason is not in testtags.php
The rain info is likely the cause of the issue since no rain has been recorded, so the last rain date is 'null'.
Change <?php $_array = split_hash_date($dateoflastrainalways) ?>
<?php echo rdate($RecDateF, $_array[1], $_array[0], $_array[2]); ?> <br/>
<?php echo "at " . $timeoflastrainalways; ?>
to <?php if($dateoflastrainalways !=="---") {$_array = split_hash_date($dateoflastrainalways) ?>
<?php echo rdate($RecDateF, $_array[1], $_array[0], $_array[2]); ?> <br/>
<?php echo "at " . $timeoflastrainalways;
} else { print "N/A"; } ?>
