Samsung's most important phone launch is this week, but everyone's going to be talking about the Apple Watch instead

April 10 is going to be a big day in tech.

The two most important Android phones of the year, Samsung's Galaxy S6 and HTC's One M9, officially launch in the US that day.

It's also the first day you'll be able to preorder the Apple Watch and try one on at the Apple Store.

The HTC phone, which got lukewarm reviews, probably won't make much of a splash, but it's particularly bad timing for Samsung.

Over the last year, Samsung has seen its profits fall as sales of its mobile devices continue to plummet. For the first quarter of 2015, Samsung expects profits to be down about 30% year over year. The Galaxy S6, which has a premium design and got spectacular reviews, is Samsung's bet to reverse that trend and get people buying its pricey Android phones again.

But the timing couldn't be worse for Samsung. The Galaxy S6 launch is going to be overshadowed by the Apple Watch on April 1o. The first round of reviews for the Apple Watch will likely come out some time this week. After that, preorders will begin at midnight Pacific on April 10. And later that morning people will start flooding Apple Stores to try the device in person.

This is the first time anyone outside Apple, the press, and a few select app developers will get to see the Apple Watch in person. It's going to be big.

It'd be a shock if we saw that kind of hubbub for the Galaxy S6 launch, a bad sign for the launch of the company's most important phone ever.