In 2017, I did the poem a day challenge in April — National Poetry Month. And, I started the 52-Week Writing Challenge the same year but that was once a week. I didn’t quite complete it due to unexpected company that stayed with us for 10 days — my computer is in our guest room.
The poem challenge was tough because we were in the loan process to buy a house and in the midst of downsizing and packing to move. But, I did it! A poem every day for 30 days.
I think choosing one topic for 103 days is making the challenge unnecessarily difficult. How about if you make it an open challenge and post 6 topics for each week (allowing a day of rest)? Participants could choose which topics to write about on which days during the week but all six topics would have to be used during that week. You could randomly choose the topics or use one of those online writing prompts. Just an idea.