RSS pubdate

I have set up snippets for our content types to generate the specific entries for an RSS feed. The issue I am having is with populating the “pubDate” field. This is ideally supposed to be the time the item was published to the website. I currently have 2 options to do this, but there are issues with both:
[ul]Enter the pubDate field manually on the CE. Obviously, this will get us the correct timestamp, but it has to be manually entered on each item
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[ul]Use the sys_pubdate value. This is automated, which is great, but if the item is re-published, the sys_pubdate gets updated, and provides a false value for the RSS feed (it should always remain as the original pub date)
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Any thoughts on another sys field that I could use to automatically capture the initial pub date, and keep that value regardless of how many times it is re-published?

I take it you don’t want your content start date (sys_contentstartdate) to be the same as your pub date?

We created a shared field for Published date which is used on News articles and RSS feeds. It is set manually so not affected by republishing the item.

I take it you don’t want your content start date (sys_contentstartdate) to be the same as your pub date?

Correct, because they sometimes put an item in many hours before it is published.

We created a shared field for Published date which is used on News articles and RSS feeds. It is set manually so not affected by republishing the item.

We also have a shared field, but wanted to find a way to make it an automated process instead of manual…