# Bug? Writing to DateTime memory tag not functioning as anticipated 8.1.33

**URL:** <https://forum.inductiveautomation.com/t/bug-writing-to-datetime-memory-tag-not-functioning-as-anticipated-8-1-33/110059>\
**Category:** Ignition\
**Tags:** ignition81\
**Created:** [August 21, 2025, 5:58pm UTC](https://forum.inductiveautomation.com/t/bug-writing-to-datetime-memory-tag-not-functioning-as-anticipated-8-1-33/110059 "2025-08-21T17:58:30Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![cdunn.home](https://avatars.discourse-cdn.com/v4/letter/c/45deac/32.png) [@cdunn.home](https://forum.inductiveautomation.com/u/cdunn.home)\
**Post date:** [August 21, 2025, 5:58pm UTC](https://forum.inductiveautomation.com/t/bug-writing-to-datetime-memory-tag-not-functioning-as-anticipated-8-1-33/110059/1 "2025-08-21T17:58:30Z")

</div>

I don’t know if this is a bug or intended behavior, but I was trying to write updated datetime values to a memory tag. It seemed to have no effect, but still return good quality.

This is the tag I created, complete with a starting value.

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/5/4/5420ecc7bd42028aa41f1f576d0be11a75584dc1.png)

I could see the Value did not change using my original code, so I tried this test code just to make SOMETHING happen:

```python
>>>system.tag.writeBlocking(["[FCE_Tags_09]Diagnostics/LastAnalysisTimestamp"], [None])

```

…which resulted in **no change to the value** , but returned:

```python
[Good]

```

After banging my head on the desk several times, I finally realized it was reading and writing to the “ **Timestamp** ” property because that was part of the tag name! I changed the tagname to end with “Time” instead of “Timestamp”, and now it works as expected!

I was under the impression the system would look for a property separator, and otherwise use the “value” property.