陰暦

1. Origins, structure, and basic meaning

• Structure: 陰暦 (いんれき) is a noun for a calendar system that reckons dates by lunar cycles.
• Basic usage: 陰暦で日付を確かめる uses the lunar calendar as the reckoning system, while 陰暦と新暦の日付 places it alongside the modern solar calendar for comparison.

2. Common pitfalls and similar expressions

• System marker で and coordination と
  • In 陰暦で, で marks the calendar system used to check a date. In 陰暦と新暦, と coordinates two systems; it does not state that the two dates have the same value.