If you want to charge cellphones and laptops, getting foldable solar panels to charge a battery bank, like a Jackery, should be pretty simple and wouldn’t require much, if anything, in terms of doing your own electrical work.
If you want something bigger, or to do your own electrical work, that can get a lot more involved, depending on the scope of your project.
And it is easily extensible to YYYY-MM-DDThh:mm:ss to include the time of day