Upvote:4
You should be fine. Article 6, paragraph 2 of the Schengen Borders Code says:
For the purposes of implementing paragraph 1, the date of entry shall be considered as the first day of stay on the territory of the Member States and the date of exit shall be considered as the last day of stay on the territory of the Member States. Periods of stay authorised under a residence permit or a long-stay visa shall not be taken into account in the calculation of the duration of stay on the territory of the Member States.
(Emphasis added.)
In fact, you can stay a few more days, because you've made a couple of mistakes in your calculation. First, since 7 April and 7 July appear to be covered by your work visa, you should not count them in your 90/180 calculation. Second, days are counted inclusively. So your first chunk of days is 66 days from 1 February through 6 April, inclusive. Your second chunk of days is from 8 July through 30 July, inclusive, for a total of 23 days.
But on 30 July, you have only 88 days of presence, because the 180-day period that ends on 30 July starts on 2 February. You therefore hit 90 days on 2 October, so you have to leave the Schengen area before midnight on that date.
This assumes that you don't set foot in any Schengen country other than Poland during the period 7 April through 7 July. If you do, you'll have to reconsider the calculation. If you spend enough days outside Poland, in fact, you might need to leave as soon as your work visa expires.