Is the date in this German sentence the date of invite, or date of the event?

[edmont]

Is the date in the below sentence when Karl got the request for a lecture? Or when he gave the lecture?

Auch im Arbeiterrat Groß-Stuttgarts, wo Karl aufgrund eines Antrages einer Gruppe von Arbeitern am 7. Mai Gelegenheit zu einem Vortrag bekam, fanden seine Ideen nur eine reservierte Aufnahme.

Thank you for any assistance.

[Adrox98]

He got the opportunity to give a lecture at 7. may

[Duckduck]

He got the opportunity to give a lecture on 7 May.

Hi Adrox98,
I'm not sure if this answer clears things up for edmont...

Hi edmont,
I'm quite sure the lecture was the given on 7 May, because
1. Why should the date of the request for a lecture be important or even mentioned?
2. The fact that Karl's ideas didn't exactly make the audience raise the roof lets us assume that the lecture was already given.

And once again   Have a nice weekend!
Duckduck

[edmont]

Adrox98 and Duckduck, thank you!  It is now very clear.  And both of you have a great weekend!