Twin dates?

Would that be a reference to the time of year? Gemini is the sign with the twins. Farmers relied on the signs in the sky for their crops.

I heard mention of 'twin days.' I believe it's to do with propitious time to sow crops. It sounds a bit quaint but I think crop-sowers believed that they should wait for two days of the same weather before they decided to start sowing. The US sowing season starts around the beginning of March when the weather is still volatile. So probably two good days of fair weather at that time of the year was the sign they were waiting for.