… I’ve googled this and still can’t find an explanation in straightforward, plain English.
Year-to-date means “since January 1st of this year”
Year-over-year means “over the last 365 days”.
Do I have that right?
Yes.
Yes. (This one’s for you, Discourse).
Slight quibble: “Year to date” means “since the date that is the start of the current year”. For most contexts, that’s January 1, but it might instead be a business’s fiscal year, or a school year, or the like.
[Moderating]
Oh, and I’ve edited your title to make it more descriptive. Please use descriptive titles on your threads.
Not necessarily.
In my experience, “year over year” is usually used to compare one actual year (calendar year, or sometimes fiscal year) to the previous one, rather than “over the past 365 days.”
I’ve seen YoY used to mean comparing some period in the current year with the same period in the previous year. For example, here’s a headline I found with a quick google: “Maruti Suzuki records 6% YoY fall in April auto sales”. I’ve seen similar use of YoY comparing a just completed quarter with the same quarter the year before.
Agreed. If someone says their store’s profit has increased 20% year over year. It would be a 20% increase for a given period vs that same period one year earlier.
“Over the past 365 days” would be a “trailing year” or trailing twelve months/TTM.
That’s also how I know YoY. It’s used in that sense, for instance, when giving inflation rates. You might read, for instance, that inflation reached 8 % yoy in May, which does not mean prices rose, on average, by 8 % during the 31 days of May but rather that they rose by 8 % from May 2021 to May 2022.
Isn’t “this time this year compared to this time last year” the same thing as “over the past 365 days”?
No. Comparing what happened in April of this year with April of last year is not the same. What happened in the intervening 11 months is not a factor in that comparison. Similarly if the period is a quarter (ignore the intervening 3 quarters) or even YTD YoY (where the periods compared are from the beginning of the year to the current date; ignore the rest of the year). If you want the last 365 days, use the term “trailing year”.
If I say “Sales are up 5% over the past 365 days”, that could mean that there was a steady increase, it could mean that it increased 10% and then fell back down to 5, it could mean that it oscillated erratically between now and then. What happened in between isn’t part of that statement; all I need to look at is two data points, what sales were 365 days ago and what they are now.
At least, if I’m just giving a number. If I’m showing a graph of a year’s worth of data, then yes, there’s a difference. But for just a number, I don’t think there is a difference.
+1
I work for a Japanese multinational in Australia and hence YTD can mean either from 1st Jan, or from 1st Jul (Australian fiscal year) or from 1st Apr (Japanese fiscal year).
It’s not overly confusing because the contexts are usually clear.