Dallas DS1287 / DS12887 / DS12B887. Benchmarq BQ3287. 1 - BQ3285LF RTC IC SSOP24. This is NOT a beginner project, and requires soldering a few small SMD components. The RTC IC may give you trouble. I solder the components in this order: RTC IC, Crystal, [Clean Flux], Pin headers (where they wont obstruct battery holder), [Clean Flux], battery holder, then the last few header pins next to the battery holder.
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