Commonly used for Valentine's Day and Easter, pink is sometimes referred to as "the color of love." The use of pink as distinctive of girls can be dated back at least to 1868. The phrase "pink-collar worker" refers, in the West, to persons working in fields or jobs conventionally regarded as "women's work". Whereas Jewish people were forced to wear a yellow star of David under Nazi rule, men imprisoned on accusations of homosexuality were forced to wear a pink triangle. Nowadays, a pink triangle (sometimes pointing up, contrary to Nazi usage) is often worn with pride. Seeing pink elephants is a euphemism for hallucinations caused by delirium tremens. In Thailand, Pink is associated with Tuesday on the Thai solar calendar.