以降

1. Origins, structure, and basic meaning

• Structure: 以降 is read as いこう and is an expression placed after a time point to mark a range from that point onward, including the reference point, or a period continuing since then.
• Basic usage: Saying that one can meet from three o’clock onward appears in 三時以降なら会える, while describing diary writing that has continued since spring appears in 春以降、日記を続ける.

2. Common pitfalls and similar expressions

• Difference from 以前
  • 以降 points from the reference time onward rather than before it.