Employees’ multitasking approach to managing time has been considered desirable in today’s dynamic business world. Yet, its detrimental effects on employee well-being have rarely been recognized and investigated. Building upon resource drain theory, we operationalized this time management approach with employee polychronicity and built a theoretical model to test its relationship with interdomain conflicts and employee well-being with a time-lagged research design and multi-sourced data. We found that approaching time polychronically led employees to juggle work and family tasks simultaneously, experience intensified work-family conflicts, and therefore suffer from burnout syndromes. We further found that this undesirable side of polychronic time management can be weakened by a supportive work environment characterized by organizational support for work-family boundaries and creative family-supportive supervisor behaviors.