As it is the law of nature, that in general a proportion of time, by God's appointment, be set apart for the worship of God, so by his Word, in a positive moral, and perpetual commandment, binding all men, in all ages, he has particularly appointed one day in seven for a sabbath to be kept holy unto him,28 which from the beginning of the world to the resurrection of Christ was the last day of the week, and from the resurrection of Christ was changed into the first day of the week, which is called the Lord's Day:29 and is to be continued to the end of the world as the Christian Sabbath, the observation of the last day of the week being abolished. (London Baptist Confession of Faith 22.7)
I would not personally refer to Sunday as the Christian Sabbath, but that's basically the only place I would disagree with the LBCF on this issue. God set aside the seventh day for the people of Israel to rest; while there's no positive commandment in the New Testament to rest on the first day, we see by the example of the apostles and the early church that they met to break bread and worship together on the first day of the week (e.g. Acts 20:7, 1 Cor. 16:2).
Hebrews 10:25 also says not to give up meeting together, but it's important to keep in mind the context: the letter is written to Christians who are under pressure to give the faith up entirely, not merely to Christians who might, on occasion, skip church. Still, there's a principle there and in the aforementioned verses that the church meets together regularly on the first day of the week, and barring necessity, we should make an effort to be there as well. This isn't a
law, so if missing out on church is unavoidable, you shouldn't feel guilty about missing it. The classic confessions of the faith have usually made accommodations for "works of necessity"--things like tending to farm animals, emergency work, and so forth, that don't take a break on Sundays. Even Jesus said it was lawful to break Sabbath to rescue an animal (and unlike Sunday worship, Sabbath-keeping
was a law).
So if your job takes you away from Sunday services periodically, don't beat yourself up over it, and strive to be there when you're able. Of course, it's better to attend than not--and if your work takes you away from church an inordinate amount of time, it might actually be wise to seek other work if you're able. Just don't be legalistic about it.