Dutch reckoning

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun idiomatic, uncommon, obsolete, slang A (falsified) bill that is not itemised, and that is unjustifiably high.
• noun nautical a false or incorrect reckoning of position.
• noun Used other than as an idiom. as reckoned by the Dutch: five o'clock by the Dutch reckoning would be five o'clock in the Dutch rather than, e.g., a Canadian time zone; for example, 1 March 1625 in the Dutch reckoning was, in the English reckoning of the time, 19 February 1624(?).