Completing missions at the contact - timing

[HornyBeast]

I wanted to visit the contact that gave me a mission to complete it.

I am on GMT (Eastern +5) during the winter, GMT+1 in the summer as it is now.

 

It told me I couldn't complete the mission until 10:47 my time, OK, I came back at 11:30. Still wouldn't complete. I assumed it was because this was on some US time. Enabled the timestamp in chat to try to get a clue, nope, that showed my time correctly.

Tried again at 11:47 and it completed.

Is there something wrong in the summer time calculation ? (the hour doesn't change for some time yet here, so that's not the issue, both the previous timing and this one are summer time)