And it is not easy to always work giving of your best. Yet the idea of work, for the Reformed church, is not that one is always earning bread and butter. Work is part of what you do when you play or worship or any of the activities through the day. We offer everything we do up to God and so we work to make it the best that we can do.
John Calvin often has a reputation as a dour, censorious man. But he played at bowls on Sunday and part of his salary was more than a tun (I never can remember how much this is but it is over 200 gallons) of wine. While I suspect Calvin could be as his reputation sometimes is stated, that doesn’t mean he was always like that and judging from the quantity of wine in his salary and the fact that he played games I suspect those dour, censorious parts are just part of the man. The idea of work as something to be endured is just not a part of Reformed theology.
Work is celebrated and enjoyed. Work is about offering your best. Work is about more than accumulation. Work is for the glory of God.
Malachi 1:1, 6-14
 An oracle. The word of the LORD to Israel by Malachi.  A son honors
his father, and servants their master. If then I am a father, where is the honor
due me? And if I am a master, where is the respect due me? says the LORD of
hosts to you, O priests, who despise my name. You say, "How have we despised
your name?"  By offering polluted food on my altar. And you say, "How have we
polluted it?" By thinking that the Lord's table may be despised.  When you
offer blind animals in sacrifice, is that not wrong? And when you offer those
that are lame or sick, is that not wrong? Try presenting that to your governor;
will he be pleased with you or show you favor? says the LORD of hosts.  And
now implore the favor of God, that he may be gracious to us. The fault is yours.
Will he show favor to any of you? says the LORD of hosts.  Oh, that someone
among you would shut the temple doors, so that you would not kindle fire on my
altar in vain! I have no pleasure in you, says the LORD of hosts, and I will not
accept an offering from your hands.  For from the rising of the sun to its
setting my name is great among the nations, and in every place incense is
offered to my name, and a pure offering; for my name is great among the nations,
says the LORD of hosts.  But you profane it when you say that the Lord's
table is polluted, and the food for it may be despised.  "What a weariness
this is," you say, and you sniff at me, says the LORD of hosts. You bring what
has been taken by violence or is lame or sick, and this you bring as your
offering! Shall I accept that from your hand? says the LORD.  Cursed be the
cheat who has a male in the flock and vows to give it, and yet sacrifices to the
Lord what is blemished; for I am a great King, says the LORD of hosts, and my
name is reverenced among the nations.