def get_subj_exp_sess_date_matcher():
    """Describe relationships between experiments and when they took place for _sleep subjects

    Returns
    -------

    """
    SUBJ_EXP_SESS_DATE_MATCHER = {'R1207J': {'catfr1': {'0':
        '08_17_16_1543_1610', '1': '8_18_16_1530_1610'}, 'fr1': {'0':
        '8_20_16_1021_1105'}}, 'R1230J': {'fr1': {'0': '10_09_16_1400_1500',
        '2': '10_12_16_1138_1227', '4': '10_13_16_1520_1615', '5':
        '10_14_16_1017_1114', '6': '10_17_16_1320_1409'}, 'catfr1': {'0':
        '10_10_16_1220_1307'}}, 'R1293P': {'catfr1': {'0':
        '04_17_17_0955_1055'}, 'fr1': {'1': '04_18_17_1625_1715'}},
        'R1348J': {'catfr1': {'0': '09_26_17_1540_1630'}, 'dboy3': {'0':
        '09_23_17_1506', '1': '09_26_17_1449', '2': '09_27_17_1533'}},
        'R1384J': {'catfr1': {'0': '09_26_17_1540_1630'}, 'dboy3': {'0':
        '02_01_18_1825', '1': '02_03_18_1810', '2': '02_03_18_1812', '3':
        '02_07_18_1732', '4': '02_07_18_1734', '5': '02_10_18_1827', '6':
        '02_10_18_1828'}, 'dboy1': {'1': '02_17_18'}}}
    return SUBJ_EXP_SESS_DATE_MATCHER
