Lammas / Lughnasadh (August 1st)
The closest public holidays to Lammas are Ocean Day (Umi no Hi) on the third Monday of July, or Mountain Day (Yama no Hi), which is a brand new public holiday that will be observed for the first time on August 11th this year. These days might seem a little too distant from Lammas to really be a good time for Pagans to commemorate this Sabbat. However, it is interesting that both these holidays relate to nature and Pagans could consider celebrating these otherwise secular observing in a Pagan way. Ocean Day would be a good day to commemorate the deities of water and the sea in your particular pantheon, and Mountain Day for celebrating deities of the mountains, forests and wild places.