"... Winter Solstice ...:" December 21 is the shortest day of the year - in the Northern Hemisphere. In places like Australia and Indonesia which are below the equator, it is the longest day of the year.
I point that out to you because December 21 also happens to be my birthday. It wasn't until I was in my mid-40's that I finally figured out that my birthday got the same 24 hours as everyone else, I just didn't get as many daylight hours as everyone else.
Some years ago the International Republican Institute asked me to fill in on a training mission they had going to Jakarta. They said I had to leave about December 15 but they promised they could get me home in time for Christmas if I left the evening of the 20th and would get home on the 22nd - the International Dateline being involved in some manner.
I said I would do it, but only if I could spend December 21st in Indonesia because I had made a promise to myself that at least once in my life, I would spend my birthday in a place where it was the longest day of the year.
We struck a deal. They paid for the slight additional airfare, I paid all the other expenses and I got to spend a very, very long day in ... Bali.