Don't know if this adds anything but these are the rules regarding rugby fixtures
FIXTURES AND KICK-OFF TIMES
4.1 Arrangement of Fixtures
(a) All Match weekends to be played during a Season shall be arranged as soon as reasonably practicable following the end of the immediately preceding Season by PRL (within the Season structure approved from time to time by the PGB) and a list of such Matches shall be sent to each of the Clubs.
(b) All Clubs shall confirm to PRL the dates and kick off times of the fixtures on the weekends as notified by the PGB by 1 July in each year or on such other date as determined by the PGB.
(c) All Matches shall be played on the dates scheduled in the published Fixture List save (i) where both clubs agree to rearrange a fixture and PRL has given its written approval or (ii) where PRL decides to rearrange a fixture. Before making any decision PRL shall notify the RFU’s Professional Rugby Director and keep the RFU’s Professional Rugby Director informed of all issues relating to or arising from the decision. Such decision shall be binding on the Clubs, PRL and the RFU.
(d) A Premiership League Match kick-off must, so far as possible, adhere to the time on the published fixture list or any change to that time approved by PRL and the Referee must report to PRL a delay in kick-off of more than ten Premiership Regulations 2017-2018 Page 22 of 54
minutes. Before making any decision in relation to changes in the time of any Match kick-off, PRL shall notify the RFU’s Professional Rugby Director and keep the RFU’s Professional Rugby Director informed of all issues relating to or arising from the decision. Such decision shall be binding on the Clubs, PRL and the RFU.
these are the EFL rules
26 Administration and Arrangement of Fixtures
26.1 All League Matches shall be arranged as soon as practicable. The intellectual property rights and all other rights in all lists of arrangements of such fixtures (if any) shall be vested in The League.
26.2 Any dispute between two or more Clubs as to the arrangement of League Matches shall be referred to and decided by The League, and The League shall have absolute discretion in that respect. All re-arrangements of League Matches must be submitted to and approved by The League.
26.3 However, where a Club is selected to play in a televised Match played under the auspices of The League on a Thursday evening, and that Club is also scheduled to play on the immediately following Saturday ('Saturday Match'), the Club shall have the right to request that The League reschedule the Saturday Match to the immediately following Sunday i.e. a 24 hour postponement. Approval for any such request shall not be unreasonably withheld or delayed. Where applicable the provisions of Regulation 26.4 will also apply.
26.4 Further, where:
26.4.1 a League Match is scheduled to be played on a Tuesday (‘Tuesday Match’);
26.4.2 the Home Club and/or the Away Club in that Tuesday Match is required to play on the immediately preceding Sunday (‘Sunday Match’) because of matters outside its control including, by way of example and without limitation, police requirements, television or cup commitments;
26.4.3 the Sunday Match was not scheduled to be played on that Sunday in the first i.e. the draft fixture list published by The League in the immediately preceding Close Season;
26.4.4 neither the Home Club nor the Away Club are scheduled to play on the immediately following Thursday or Friday; and
26.4.5 either the Home Club or Away Club in the Tuesday Match requests (giving not less than 28 Clear days’ notice prior to the originally scheduled Tuesday date) that the Tuesday Match be rescheduled, (together the ‘Conditions’ and each a ‘Condition’) the, provided all Conditions are satisfied the Tuesday Match shall automatically be rescheduled to take place on the immediately following Wednesday i.e. a 24 hour postponement. For the avoidance of doubt, where one Condition (or more) is not satisfied, the
matter shall be determined by The League in its absolute discretion, whose decision shall be final and binding.
26.5 Dislocation of League Matches from any cause whatever shall be immediately reported to The League by the Clubs concerned and it shall be the duty of the Home Club in each instance immediately to notify the appointed Referee and Assistant Referees of such dislocation
EFL Ground sharing rules
13.4 Ground sharing will only be approved at the discretion of the Board.
13.5 Except in cases where a Club seeks consent to enter into a ground-sharing agreement with another Club, it shall be a condition of any such consent that the ground-sharing agreement shall contain provision to ensure that:
13.5.1 the playing of any of the Club’s first team matches will always take precedence over the activities of the other party to the agreement; and
13.5.2 the Club shall have the ability to postpone other activities scheduled to take place on the pitch in the immediately preceding 48 hour period where in the opinion of the Club, acting reasonably, there is a risk that such activity may result in the subsequent postponement or abandonment of a match to be played under the auspices of The League.
13.6 Each Club shall register its ground with The League and no Club shall remove to another ground (whether on a temporary or a permanent basis) without first obtaining the written consent of the Board, such consent not to be unreasonably withheld and the Board shall be entitled, if granting consent, to impose such conditions as it deems appropriate in all the circumstances.
13.7 In considering whether to give any consent to a permanent relocation, the Board shall have regard to all the circumstances of the case (including, but not limited to the factors set out in this Regulation 13.7) and shall not grant consent unless it is reasonably satisfied that such consent:
EFL length of agreement
13.9 Subject to any dispensations granted by the Board, a Club shall either own its ground or have a legally enforceable agreement with its ground's owner for its use by the Club, expiring not earlier than the end of the current Season.