1 week ~ 4 weeks: every week 6 weeks:
2018: March 12, April 9, May 7, June 4, July 2, September 3, October 1, October 15 8 weeks:
2018: March 12, April 9, May 7, June 4, July 2, September 3, October 1, October 15 12 weeks:
2018: March 12, April 9, May 7, June 4, July 2, September 3