おきにAt regular intervals
おきに places repeated events or objects at regular measured intervals. The quantity before it indicates the spacing between one occurrence and the next.
How the interval is counted
With separate countable units such as calendar days, the clearest pattern treats the stated number as the units left between occurrences. Thus 一日おきに means that one day is left in between, while 二日おきに leaves two days in between.
Seeing the actual dates
植物の成長を月曜日から二日おきに記録します。記録日は月曜日、木曜日、日曜日です。
We will record the plant's growth every third day starting Monday. The recording days are Monday, Thursday, and Sunday.
AnalyzeTuesday and Wednesday lie between the first two recording days, so there is a two-day gap.
Gap counting versus every unit
おきに prototypically names the gap before the next occurrence. By contrast, ごとに distributes something over successive units and normally means “every X units.” The difference is especially clear with days.
Time and distance
With continuous measurements such as minutes or meters, the expression often describes the distance from one occurrence point to the next.
More examples
この薬は一日おきに使ってください。
Please use this medicine every other day.
Analyze点検は二日おきに行われます。
The inspection is carried out every third day, with two days between inspections.
Analyze会場では一席おきに座ってください。
At the venue, please leave one seat between people.
Analyze苗を一メートルおきに植えました。
We planted the seedlings at one-meter intervals.
Analyzeマラソンコースには五キロおきに給水所があります。
There are water stations at five-kilometer intervals along the marathon course.
Analyzeシステムは六時間おきにデータを保存します。
The system saves the data at six-hour intervals.
AnalyzeFor an operational schedule, list the actual save times as well.