print(string.match("2017-03-15 - 2017-03-15", '^(%d+%-%d+%-%d+) %- %1$') ~= nil)
print(string.match("Some longer text: 2017-03-15 - 2017-03-15 and more here", '(%d+%-%d+%-%d+) %- %1') ~= nil)
print(string.match("Some longer text: 2017-03-15 - 2017-03-15 and more here", '(%d+%-%d+%-%d+) %- %1') ~= nil)
print(string.match("Some longer text: 2017-03-15 - 2017-03-15 and more here", '%f[%d](%d+%-%d+%-%d+) %- %1%f[%D]') ~= nil)
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