By default, all time series data that is accessible from the Solcast API is in Coordinated Universal Time, or UTC. We often get asked why we don't convert our data from UTC to a specific local time.

Briefly, here's 2 reasons why we don't do this:

Working with dates is tricky
Whilst we relish the opportunity to get our hands dirty with a worthy challenge, working with dates is one of those problems that only keep on giving. There are some whom work with dates regularly and have published their opinions. Here is a sample:

  1. NodaTime Trivia (the author of a popular Date/Time library for many languages describes some of the edge cases he's found)

  2. Bad Timing (a subreddit reddit post on why dates and times are hard work)

  3. The Time & Zone Fallacies believed by Programmers

As is the case for many businesses, there is only so much effort and resources available. We'd prefer to spend our effort towards improving our forecasting capabilities rather then getting bogged down in date complexities.

Which timezone?
Pushing past the complexities of dates, let's assume we'd go ahead anyway. If we decided to support automatic local time conversion, there are a number of different ways we could allow timezone to be configured within a request:

  1. Via a fixed offset (e.g. +10 or -5) 

  2. Via a legal time zone (e.g. PST or AEST) 

  3. Via the longitude of the location in the request (e.g. 1 hour every 15 degrees) 

  4. Via a nominated TZDB ID (e.g. Australia/Sydney)

Each of these methods has their own advantages and disadvantages (which won't be discussed here). If we chose to support one of these, it may end up suiting a particular group of users, but may also frustrate another group of users. 

How can we help you convert to local time?
We still want to help you convert time series data for your own use. You may want to validate Solcast data against one of your own data sets, and the difference between the dates in the two datasets is making a manual comparison difficult. You may be carrying out your comparison using Excel spreadsheets or files in csv format. If this is you, we have a tool for you that may help you out.


The above is a link to an excel spreadsheet that contains a tool to convert time series data retrieved from the Solcast API and applies a fixed offset to it. 

The spreadsheet contains specific instructions on how to use the tool, but in a nutshell you would follow the below steps:

  1. Within the csv file containing Solcast API data, copy the column containing the time series you want to convert.

  2. Paste the time series into the first column of the solcast-timezone-converter spreadsheet

  3. Identify the fixed offset you want applied to the time series data (10 or -5, or some other offset). The tool will then apply the offset to the time series into a new column

  4. Copy and paste the updated time series data with applied offset back into your original csv file

How else can we help you?
Got any ideas on how else we can support you in converting time series data? Reach out to us at

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