Old Style

noun

1. historical, uncountable The Julian calendar system, especially with reference to Russia, where it continued to be used until the early 20th century. The banded ones were all dressed in white gowns — a gay survival from Old Style days, when cheerfulness and May-time were synonyms — days before the habit of taking long views had reduced emotions to a monotonous average.
2. historical, uncountable A dating system in which March 25 is the New Year's Day.