にわたって

「にわたって」indicates an action or state occurring over a period of time or throughout a certain space.
「にわたって」and 「にかけて」have similar meanings, but they differ in:
- 「にかけて」specifically indicates the starting and ending points of the time/space range (～から～にかけて).
- 「にわたって」does not specify the exact starting and ending points of the time/space range, instead it indicates the whole duration or span of that time/space.