Developed is a theoretical framework for localized, dynamic spacetime configurations, the definingcharacteristic of which is not primarily a spatial concentration of energy, but rather a locally alteredproper-time structure. The starting point is a self-coupled real scalar field whose energy-momentumtensor generates a spherically symmetric spacetime curvature via the Einstein equations. The localproper time is determined by the time-dependent metric component (g tt ) .Examined then is bothstatic and oscillating configurations, demonstrating that a harmonic evolution of the scalar field—comprising odd harmonic s=s( ω ;3 ω ;5 ω ;...) —is naturally coupled to even harmonics ofh=h(0 ;2 ω ; 4 ω ;...) of the metric. This provides a mathematically precise foundation for anoscillating "time bubble." The frequently encountered ( N=2n+1) structure is identified here as aharmonic structure, rather than being interpreted as an established quantization of proper time.The resulting problem is a nonlinear, self-consistent eigenvalue problem for the scalar field and thespacetime metric. The existence, stability, lifespan, and potential discrete spectrum of such solutionsmust be investigated numerically. In particular, a possible Planck-scale quantization of proper timeis formulated as a testable spectral hypothesis.