Yup, it is schedule. I think I once spelled it that way as well.
I assume google translate automatically corrects for spelling when translating. If you translate the misspelled word "schedual" to chines, for example, you get 附表. Translating 附表 back to english you get the correctly spelled "schedule." So, google translate knows how to spell schedule, it just automatically corrects the spelling during translation. I use google translate. It's not perfect, but it is very good considering what it does.