Breaking a string on dates - php

Question

I am using the following script I have altered to split a large string into sentances. However I am having issues getting it to also break on dates.
Original working code:
$re = '/# Split sentences on whitespace between them.
(?<= # Begin positive lookbehind.
[.!?:] # Either an end of sentence punct,
| [.!?:][\'"]
| [\r\t\n] # or end of sentence punct and quote.
) # End positive lookbehind.
(?<! # Begin negative lookbehind.
Mr\. # Skip either "Mr."
| Mrs\. # or "Mrs.",
| Ms\. # or "Ms.",
| Jr\. # or "Jr.",
| Dr\. # or "Dr.",
| Prof\. # or "Prof.",
| U\.S\.A\.
| Sr\. # or "Sr.",
| T\.V\.A\. # or "T.V.A.",
| a\.m\. # or "a.m.",
| p\.m\. # or "p.m.",
| •\.
| :\.
| •\.
# or... (you get the idea).
) # End negative lookbehind.
\s+ # Split on whitespace between sentences.
/ix';
$sentences = preg_split($re, $block_o_text, -1, PREG_SPLIT_NO_EMPTY);
for ($i = 0; $i < count($sentences); ++$i) {
I have added [0-9]/[0-9]/[0-9], but it doesn't seem to be having the desired effect. What am I missing? Here Is my updated code below:
$re = '/# Split sentences on whitespace between them.
(?<= # Begin positive lookbehind.
[.!?:] # Either an end of sentence punct,
| [.!?:][\'"]
| [\r\t\n] # or end of sentence punct and quote.
| [0-9]/[0-9]/[0-9] # or on a date
) # End positive lookbehind.
(?<! # Begin negative lookbehind.
Mr\. # Skip either "Mr."
| Mrs\. # or "Mrs.",
| Ms\. # or "Ms.",
| Jr\. # or "Jr.",
| Dr\. # or "Dr.",
| Prof\. # or "Prof.",
| U\.S\.A\.
| Sr\. # or "Sr.",
| T\.V\.A\. # or "T.V.A.",
| a\.m\. # or "a.m.",
| p\.m\. # or "p.m.",
| •\.
| :\.
| •\.
# or... (you get the idea).
) # End negative lookbehind.
\s+ # Split on whitespace between sentences.
/ix';

Answer 1

Dates do not have only single digits especially in the year. You need to account for that. You also need to escape the / since that is your regex delimiter.
[0-9]{1,2}\/[0-9]{1,2}\/[0-9]{2,4}